car

Abstract

To suppress a sense of discomfort given to a driver during automatic parking.SOLUTION: At the time of automatic parking, a control device controls an engine and a braking device so that an automobile travels on the basis of vehicle target driving force with the adjustment of driving force by the idling control of the engine based on a target revolution speed and of braking force by the braking device to move to a target parking position. In this case, at the time of the automatic parking, the control device sets the maximum value of a request revolution speed based on whether or not the warming-up of a catalyst is required and a comparative revolution speed as the target revolution speed of the engine. Here, a first request revolution speed which is the request revolution speed when the warming-up of the catalyst is required is set to be higher than a second request revolution speed which is the request revolution speed when the warming-up of the catalyst is not required. The comparative revolution speed is set within a range which is equal to or lower than the first request revolution speed, and in which a difference from the first request revolution speed is equal to or less than a prescribed value.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present invention relates to automobiles. [Background technology]

[0002] Conventionally, for this type of automobile, a vehicle driving control has been proposed that controls the driving force of the engine and the braking force of the braking device to automatically move the vehicle to a target position (see Patent Document 1). In this automobile, during the vehicle driving control, a control is also performed in which the braking force is increased when the idling speed of the engine increases and the driving force increases, and the braking force is decreased when the idling speed decreases and the driving force decreases. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2019-25994 A Summary of the Invention [Problem to be solved by the invention]

[0004] In the above-mentioned automobile, the braking force is reduced when the engine idling speed is reduced and the driving force is reduced, but the reduction in the braking force may be delayed relative to the reduction in the idling speed. In particular, when the idling speed is significantly reduced, the delay in the reduction in the braking force becomes significant, the vehicle speed becomes slower than expected, and the driver may feel uncomfortable as if the vehicle is about to stop before the target position.

[0005] The main object of the present invention is to prevent the driver from feeling uncomfortable during automatic parking. [Means for solving the problem]

[0006] The automobile of the present invention employs the following means to achieve the above-mentioned main object.

[0007] The first vehicle of the present invention is An engine having a catalyst installed in its exhaust system; A braking device that applies a braking force; a control device that controls the engine and the braking device so that, during automatic parking, the vehicle travels based on a vehicle target driving force by adjusting a driving force by idling control of the engine based on a target rotation speed and a braking force by the braking device to move to a target parking position; A vehicle comprising: The control device, during the automatic parking, sets the target rotation speed to a maximum value among a requested rotation speed based on whether or not warming up of the catalyst is necessary and a comparison rotation speed, a first required rotation speed, which is the required rotation speed when the warm-up of the catalyst is required, is set higher than a second required rotation speed, which is the required rotation speed when the warm-up of the catalyst is not required; The comparative rotation speed is set within a range equal to or less than the first required rotation speed and in which a difference between the comparative rotation speed and the first required rotation speed is equal to or less than a predetermined value. The gist of the present invention is as follows.

[0008] In the first automobile of the present invention, during automatic parking, the engine and the brake device are controlled so that the vehicle travels based on the vehicle target driving force by adjusting the driving force by engine idling control based on the target rotation speed and the braking force by the brake device, and moves to the target parking position. In this case, during automatic parking, the maximum value of the requested rotation speed based on whether or not the catalyst needs to be warmed up and the comparative rotation speed is set as the target rotation speed of the engine. Here, the first requested rotation speed, which is the requested rotation speed when the catalyst needs to be warmed up, is set higher than the second requested rotation speed, which is the requested rotation speed when the catalyst does not need to be warmed up, and the comparative rotation speed is set within a range equal to or lower than the first requested rotation speed and such that the difference from the first requested rotation speed is equal to or lower than a predetermined value. As a result, when the warm-up of the catalyst is completed (no longer necessary) during automatic parking, the engine target rotation speed is reduced from the first required rotation speed to the larger of the second required rotation speed and the comparison rotation speed, so that the engine target rotation speed is prevented from decreasing significantly, the engine rotation speed and therefore the driving force based thereon are prevented from decreasing significantly, the vehicle driving force is prevented from decreasing significantly relative to the vehicle target driving force, and the vehicle speed is prevented from decreasing significantly. As a result, it is possible to prevent the driver from feeling uncomfortable, such as being about to stop the vehicle before the target parking position.

[0009] In the first vehicle of the present invention, an air conditioner may be further provided that uses power from the engine to perform air conditioning of the vehicle interior, and the second required rotation speed may be set higher when the vehicle interior is being air conditioned than when the vehicle interior is not being air conditioned, thereby making it possible to set the second required rotation speed more appropriately.

[0010] The second vehicle of the present invention is A running engine and A braking device that applies a braking force; an air conditioning device that uses power from the engine to perform air conditioning in a vehicle interior; a control device that controls the engine and the braking device so that, during automatic parking, the vehicle travels based on a vehicle target driving force by adjusting a driving force by idling control of the engine based on a target rotation speed and a braking force by the braking device to move to a target parking position; A vehicle comprising: The control device, during the automatic parking, sets the target rotation speed to a maximum value among a requested rotation speed based on the presence or absence of the vehicle interior air conditioning and a comparison rotation speed, a first required rotation speed, which is the required rotation speed when the vehicle interior air conditioning is performed, is set higher than a second required rotation speed, which is the required rotation speed when the vehicle interior air conditioning is not performed; The comparative rotation speed is set within a range equal to or less than the first required rotation speed and in which a difference between the comparative rotation speed and the first required rotation speed is equal to or less than a predetermined value. The gist of the present invention is as follows.

[0011] In the second automobile of the present invention, during automatic parking, the engine and the brake device are controlled so that the vehicle travels based on the vehicle target driving force by adjusting the driving force by engine idling control based on the target rotation speed and the braking force by the brake device, and moves to the target parking position. In this case, during automatic parking, the maximum value of the requested rotation speed based on the presence or absence of interior air conditioning and the comparative rotation speed is set as the target rotation speed. Here, the first requested rotation speed, which is the requested rotation speed when interior air conditioning is performed, is set higher than the second requested rotation speed, which is the requested rotation speed when interior air conditioning is not performed, and the comparative rotation speed is set within a range equal to or lower than the first requested rotation speed and such that the difference from the first requested rotation speed is equal to or lower than a predetermined value. As a result, when the air conditioning in the vehicle interior is stopped, the engine target speed is reduced from the first required speed to the larger of the second required speed and the comparative speed, so that the engine target speed is prevented from decreasing significantly, the engine speed and therefore the driving force based thereon are prevented from decreasing significantly, the vehicle driving force is prevented from decreasing significantly relative to the vehicle target driving force, and the vehicle speed is prevented from decreasing significantly. As a result, it is possible to prevent the driver from feeling uncomfortable, such as being about to stop the vehicle short of the target parking position.

[0012] In the first or second vehicle of the present invention, the first required rotation speed and the second required rotation speed may be set to be smaller when the engine coolant temperature is high than when the engine coolant temperature is low, and the comparative rotation speed may be set to be higher than the second required rotation speed in at least a part of the temperature range of the coolant temperature. In this way, the target rotation speed can be set more appropriately. In this case, the comparative rotation speed may be a constant value or may be a variable value based on the coolant temperature. [Brief description of the drawings]

[0013] [Figure 1] FIG. 1 is a diagram showing an outline of the configuration of an automobile 20 according to an embodiment of the present invention. [Diagram 2] 1 is an explanatory diagram showing an example of a state in which the automobile 20 of the embodiment is automatically parked in a target parking space 90. FIG. [Diagram 3] 4 is a flowchart showing a target rotation speed setting process executed by the main ECU 30. [Figure 4] FIG. 4 is an explanatory diagram showing an example of a required rotation speed setting map; [Diagram 5] 4 is a time chart showing an example of a state during automatic parking. [Figure 6] 5 is a flowchart showing a process of setting a target rotation speed; [Figure 7] FIG. 4 is an explanatory diagram showing an example of a required rotation speed setting map; DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0014] Next, a mode for carrying out the present invention will be described using examples. EXAMPLES

[0015] 1 is a schematic diagram showing the configuration of an automobile 20 according to an embodiment of the present invention. As shown in the figure, the automobile 20 includes an engine 22, an automatic transmission 24, a brake device (braking device) 26, a steering device 28, and an electronic control unit (hereinafter referred to as the "main ECU") 30.

[0016] The engine 22 is configured as an internal combustion engine that outputs power using a hydrocarbon fuel such as gasoline or diesel, and an output shaft of the engine 22 is connected to an input shaft of an automatic transmission 24. A purification device 22a having a catalyst 22c that removes unburned fuel and nitrogen oxides from the exhaust is attached to an exhaust system of the engine 22. The operation of the engine 22 is controlled by an engine electronic control unit (hereinafter referred to as "engine ECU") 23. Although not shown, the engine ECU 23 includes a microcomputer having a CPU, ROM, RAM, flash memory, input / output ports, and communication ports. Signals from various sensors required for controlling the operation of the engine 22 are input to the engine ECU 23 via input ports. Examples of signals input to the engine ECU 23 include a crank angle θcr from a crank position sensor that detects the rotational position of a crankshaft of the engine 22, a coolant temperature Tw from a water temperature sensor that detects the temperature of the coolant of the engine 22, and a temperature Tc from a temperature sensor that detects the temperature of the catalyst 22c. Examples of such signals include an intake pressure Pi from an intake pressure sensor that detects the intake pressure of the engine 22, and an intake air amount Qa from an air flow meter that detects the intake air amount of the engine 22. The engine ECU 23 outputs various control signals for controlling the operation of the engine 22 via an output port. As operation control of the engine 22, the engine ECU 23 controls the opening degree of a throttle valve (intake air amount control), the amount of fuel injected from a fuel injection valve (fuel injection control), and the ignition timing by an ignition control valve (ignition control). The engine ECU 23 calculates the rotation speed Ne of the engine 22 based on a crank angle θc from a crank position sensor. The engine ECU 23 is connected to the main ECU 30 via a communication port.

[0017] The automatic transmission 24 is configured as a known hydraulically driven automatic transmission having, for example, a torque converter and a stepped transmission with four, five, or six forward gears and one reverse gear. The input shaft of the automatic transmission 24 is connected to the output shaft of the engine 22, and the drive shaft as the output shaft of the automatic transmission 24 is connected to the drive wheels 28a, 28b via a differential gear 28g. The automatic transmission 24 is driven and controlled by an automatic transmission electronic control unit (hereinafter referred to as "ATECU") 25. The ATECU 25 is equipped with a microcomputer having a CPU, ROM, RAM, flash memory, input / output ports, and communication ports, although not shown. The ATECU 25 performs gear shift control by turning on and off a plurality of clutches and brakes in a hydraulic circuit as actuators of the automatic transmission 24. The ATECU 25 is connected to the main ECU 30 via the communication port.

[0018] The brake device 26 is configured as a well-known hydraulically driven brake device, and is configured to be able to apply a braking force resulting from the brake depression force applied by depressing a brake pedal 48 and a braking force resulting from hydraulic pressure adjustment to the driving wheels 28a, 28b and the driven wheels 28c, 28d. The brake device 26 is driven and controlled by a brake electronic control unit (hereinafter referred to as "brake ECU") 27. Although not shown, the brake ECU 27 includes a microcomputer having a CPU, ROM, RAM, flash memory, input / output ports, and communication ports. The brake ECU 27 controls the braking force resulting from the brake depression force applied by the brake device 26 and the braking force resulting from hydraulic pressure adjustment. The brake ECU 27 is connected to the main ECU 30 via the communication port.

[0019] The steering device 28 is mechanically connected to a steering wheel (not shown) and the drive wheels 28a, 28b via a steering shaft, and is equipped with a steering actuator. The steering device 28 steers the drive wheels 28a, 28b based on the driver's operation, and also steers the drive wheels 28a, 28b by driving the actuator based on a steering signal from the main ECU 30.

[0020] The air conditioner 29 has a refrigeration cycle and a blower fan. The refrigeration cycle has a compressor, a condenser, an expansion valve, and an evaporator. The compressor is connected to the output shaft of the engine 22 via a clutch. The blower fan blows air cooled by heat exchange with the evaporator into the passenger compartment. When the air conditioner switch 29a is on, the air conditioner 29 turns on the clutch to connect the compressor to the output shaft of the engine 22 and drives the blower fan, thereby conditioning the passenger compartment using power from the engine 22. When the air conditioner switch 29a is off, the air conditioner 29 turns off the clutch to disconnect the compressor from the output shaft of the engine 22 and stops driving the blower fan, thereby not conditioning the passenger compartment.

[0021] The main ECU 30 includes a microcomputer having a CPU 31, a ROM 32, a RAM 33, a flash memory 34, and input / output and communication ports (not shown). Signals from various sensors are input to the main ECU 30 via the input ports. Examples of signals input to the main ECU 30 include an on / off signal from an air conditioning switch 29a that instructs the air conditioning device 29 to be turned on and off. Other examples of signals input to the main ECU 30 include an ignition signal from an ignition switch 40, a vehicle speed V from a vehicle speed sensor 41, each wheel speed from a wheel speed sensor 42, an acceleration α from an acceleration sensor 43, a yaw rate Yr from a yaw rate sensor 44, and a road surface gradient θr from a gradient sensor 45. Other examples of signals input to the main ECU 30 include an accelerator opening Acc from an accelerator pedal position sensor 47 that detects the amount of depression of an accelerator pedal 46, and a brake pedal position BP from a brake pedal position sensor 49 that detects the amount of depression of a brake pedal 48.

[0022] Various control signals are output from the main ECU 30 via the output port. Examples of the control signals output from the main ECU 30 include a control signal to the steering device 28, an air conditioning control signal to the air conditioning device 29, a display control signal to the display device 70, and a communication control signal to the communication device 72. As described above, the main ECU 30 is connected to the engine ECU 23, the ATECU 25, the brake ECU 27, and the like via communication ports. The main ECU 30 is also connected to a shift electronic control unit (hereinafter referred to as "shift ECU") 50, a surroundings recognition electronic control unit (hereinafter referred to as "surroundings recognition ECU") 55, and a navigation device 60 via communication ports.

[0023] The shift ECU 50 includes a microcomputer having a CPU, ROM, RAM, flash memory, input / output ports, and communication ports, not shown. A shift position signal from a shift position sensor 52 that detects the operation position of a shift lever 51 is input to the shift ECU 50 via an input port. The shift ECU 50 is connected to the main ECU 30 and the surrounding recognition ECU 55 via a communication port, and sets a shift position SP based on the shift position signal from the shift position sensor 52 and a control signal from the surrounding recognition ECU 55, and transmits the set shift position SP to the main ECU 30. The shift position SP may be a parking position (P range), a neutral position (N range), a drive position (D range), a reverse position (R range), etc.

[0024] Although not shown, the surrounding recognition ECU 55 includes a microcomputer having a CPU, ROM, RAM, flash memory, input / output ports, and communication ports. Various signals are input to the surrounding recognition ECU 55 via the input ports. Examples of signals input to the surrounding recognition ECU 55 include information on the vehicle and its surroundings from the surrounding recognition device 56 (for example, vehicle distances D1 and D2 between the vehicle and other vehicles in front and behind the vehicle, and the vehicle's running position in the lane on the road surface). Examples of the signals include an automatic driving mode switch signal from an automatic driving switch 57 that sets the automatic driving mode, and an automatic parking switch signal from an automatic parking switch 58 that is operated when performing automatic parking. Examples of the surrounding recognition device 56 include a camera, a millimeter wave radar, a quasi-millimeter wave radar, an infrared laser radar, and a sonar. The automatic driving switch 57 and the automatic parking switch 58 are attached to the steering wheel, the installation panel in front of the driver's seat, or in the vicinity thereof. As described above, the surrounding recognition ECU 55 is connected to the main ECU 30 and the shift ECU 50 via communication ports.

[0025] The navigation device 60 includes a main body 62 with a built-in control unit, a GPS antenna 64 that receives information about the current location of the vehicle, and a display 66. The control unit of the main body 62 includes a storage medium (e.g., a hard disk or SSD) in which map information and the like are stored, an input / output port, and a communication port. The map information includes service information (e.g., tourist information, parking lots, etc.) and road information for each driving section (e.g., between traffic lights and between intersections) stored as a database. The road information includes distance information, road width information, number of lanes information, area information (urban area or suburban area), type information (general road or expressway), gradient information, legal speed limit, number of traffic lights, turning radius of each curve, and the like. The display 66 is configured as a touch panel display that displays various information such as information about the current location of the vehicle and the planned driving route to the destination, and allows the user to input various instructions. When a destination is set by a user operating the display 66, the main body 62 of the navigation device 60 sets a planned driving route from the current location of the vehicle to the destination based on the map information stored in the main body 62 and the current location and destination of the vehicle obtained from the GPS antenna 64, and displays the set planned driving route on the display 66 to provide route guidance.

[0026] The automobile 20 of this embodiment configured in this manner can run in an automatic driving mode when the automatic driving switch 57 is on, and can perform automatic parking when the automatic parking switch 58 is on.

[0027] In the autonomous driving mode, the main ECU 30 controls the vehicle speed V by controlling the engine 22, the automatic transmission 24, and the brake device 26 based on the planned driving route, the vehicle's current location, and map information (e.g., legal speed limit) from the navigation device 60, and information about the vehicle and its surroundings from the surrounding recognition device 56, and also controls the steering device 28 to maintain the vehicle in its lane, change lanes, etc.

[0028] Automatic parking based on the operation of the automatic parking switch 58 is executed, for example, when the automatic parking switch 58 is operated while the brake pedal 48 is depressed and the vehicle is stopped and the shift position SP is in the D position. FIG. 2 is an explanatory diagram showing an example of a state in which the automobile 20 of the embodiment is automatically parked in the target parking space 90. Automatic parking is performed as follows. First, the driver sets the parking space recognized by the surrounding recognition device 56 and displayed on the display 66, surrounded by a dashed line and hatched, as the target parking space 90, and sets the parking orientation to park backward or forward in the target parking space 90. FIG. 2 shows a case of parking backward. Next, the target routes L1 and L2 for parking the automobile 20 in the target parking space 90 are set, and the target vehicle speed V* at each point of the target routes L1 and L2 is set. Then, the shift position SP, the engine 22, the automatic transmission 24, the braking device 26, the steering device 28 (steering), etc. are controlled so that the automobile 20 travels along the target routes L1, L2 based on the vehicle target driving force Fv* which is based on the target vehicle speed V*, and parks in the target parking space 90.

[0029] In this case, the shift position SP is controlled by the shift ECU 50 based on an instruction from the surrounding recognition ECU 55. The engine ECU 23 performs idling control on the engine 22 based on a control signal from the main ECU 30 so that the engine 22 is operated by rotation speed feedback control using a target rotation speed (target idling rotation speed) Ne*. The target rotation speed Ne* is set by the main ECU 30 through a target rotation speed setting process described later. By controlling the idling of the engine 22, a creep driving force Fc is output from the engine 22 to the driving wheels 28a, 28b via the automatic transmission 24. The creep driving force Fc is calculated, for example, as shown in Equation (1). In Equation (1), "Ne" is the rotation speed of the engine 22, "Ctc" is the capacity coefficient of the torque converter, "Ttc" is the torque ratio of the torque converter, and "Gr" is a conversion coefficient that takes into account the gear ratio, differential ratio, and tire diameter of the automatic transmission. The ATECU 25 controls the automatic transmission 24 based on a control signal from the main ECU 30 so that the automatic transmission 24 is in the first forward gear when the shift position SP is a forward position, and in the reverse gear when the shift position SP is a reverse position. The brake ECU 27 controls the brakes of the brake device 26 based on a control signal from the main ECU 30 so that a target braking force Fb* based on the vehicle target driving force Fv* acts on the vehicle (output to the driving wheels 28a, 28b and the driven wheels 28c, 28d). The target braking force Fb* is calculated as the difference between the read-ahead creep driving force Fcla based on the read-ahead rotation speed Nela of the engine 22 when it is greater than the vehicle target driving force Fv*. The read-ahead rotation speed Nela is a predicted value of the rotation speed of the engine 22 after a predetermined time, and is calculated by applying smoothing processing and rate processing to the rotation speed Ne of the engine 22 toward the target rotation speed Ne*. The predetermined time is determined in advance by experiment or analysis as, for example, the time required from when the target braking force Fb* is set until the corresponding braking force Fb acts on the vehicle. The main ECU 30 controls the steering device 28 based on information from the surroundings recognition ECU 55.

[0030] Fe=Ne 2 ·Ctc · Ttc · Gr (1)

[0031] Next, the operation of the automobile 20 of the embodiment thus configured, in particular the process of setting the target rotation speed Ne* of the engine 22 during automatic parking, will be described. Fig. 3 is a flowchart showing one aspect of the target rotation speed setting process executed by the main ECU 30. This routine is repeatedly executed during automatic parking.

[0032] 3 is executed, the main ECU 30 first inputs data such as the engine 22 cooling water temperature Tw, catalyst warm-up flag Fcw, and air conditioning flag Fac (step S100). Here, the engine 22 cooling water temperature Tw is detected by a water temperature sensor (not shown). The catalyst warm-up flag Fcw is set to a value of 1 when the temperature Tc of the catalyst 22c is lower than its activation temperature Tcref and thus the catalyst 22c needs to be warmed up, and is set to a value of 0 when the temperature Tc of the catalyst 22c is equal to or higher than the activation temperature Tcref and thus the catalyst 22c does not need to be warmed up. When the catalyst 22c needs to be warmed up, the ignition timing of the engine 22 is retarded compared to when the catalyst 22c does not need to be warmed up, thereby promoting the warm-up of the catalyst 22c. The air conditioning flag Fac is set to a value of 1 when the air conditioning switch 29a is on and the interior of the vehicle is being air-conditioned, and is set to a value of 0 when the air conditioning switch 29a is off and the interior of the vehicle is not being air-conditioned.

[0033] After inputting the data in this manner, the required rotation speed Nerq of the engine 22 is set based on the catalyst warm-up flag Fcw, the air conditioning flag Fac, and the cooling water temperature Tw (step S110), and the maximum value of the set required rotation speed Nerq and the comparative rotation speed Neref is set to the target rotation speed Ne* of the engine 22 (step S120), and this routine ends. After the target rotation speed Ne* is set in this manner, the set target rotation speed Ne* is transmitted to the engine ECU 23, and the engine ECU 23 performs idling control of the engine 22 by rotation speed feedback control using the target rotation speed Ne*. As a result, a creep driving force Fc based on the rotation speed Ne of the engine 22 is output to the drive wheels 28a, 28b.

[0034] Here, the process of setting the required rotation speed Nerq of the engine 22 in step S110 will be described. FIG. 4 is an explanatory diagram showing an example of a required rotation speed setting map. In FIG. 4, the solid line indicates the required rotation speed Nerq when the catalyst warm-up flag Fcw is set to a value of 1 (hereinafter referred to as "request rotation speed Nerq1"). The dashed line indicates the required rotation speed Nerq when the catalyst warm-up flag Fcw and the air conditioning flag Fac are both set to a value of 0 (hereinafter referred to as "request rotation speed Nerq2"). The dashed line indicates the required rotation speed Nerq when the catalyst warm-up flag Fcw is set to a value of 0 and the air conditioning flag Fac is set to a value of 1 (hereinafter referred to as "request rotation speed Nerq3"). In the example of FIG. 4, the required rotation speeds Nerq1, Nerq2, and Nerq3 are all set to tend to decrease as the cooling water temperature Tw increases. The required rotation speed Nerq1 is set to be larger than the required rotation speeds Nerq2 and Nerq3 in the entire temperature range of the cooling water temperature Tw. The required rotation speeds Nerq2 and Nerq3 are set to be the same in the temperature range where the cooling water temperature Tw is equal to or lower than the threshold value Twth1, and the required rotation speed Nerq3 is set to be larger than the required rotation speed Nerq2 in the temperature range where the cooling water temperature Tw is higher than the threshold value Twth1. In FIG. 4, in addition to the required rotation speeds Nerq1, Nerq2, and Nerq3, a comparative rotation speed Neref is also illustrated. The comparative rotation speed Neref is set within a range where the required rotation speed Nerq1 is equal to or lower than the required rotation speed Nerq1 and where the difference ΔNe from the required rotation speed Nerq1 is equal to or lower than a predetermined value ΔNeref. This comparison rotation speed Neref is further set as a constant value so that it is equal to the required rotation speeds Nerq2, Nerq3 when the cooling water temperature Tw is at a threshold value Twth2 lower than the threshold value Twth1, is smaller than the required rotation speeds Nerq2, Nerq3 in a temperature region where the cooling water temperature Tw is lower than the threshold value Twth2, and is larger than the required rotation speeds Nerq2, Nerq3 in a temperature region where the cooling water temperature Tw is higher than the threshold value Twth2.

[0035] FIG. 5 is a time chart showing an example of the state of the catalyst warm-up flag Fcw, the target rotation speed Ne* and rotation speed Ne of the engine 22, the look-ahead rotation speed Nela, the vehicle target driving force Fv*, the vehicle driving force Fv, the creep driving force Fc, the braking force Fb, the target vehicle speed V*, and the vehicle speed V during automatic parking. In the figure, the solid line shows the state of the embodiment, and the dashed line shows the state of the comparative example, and the catalyst warm-up flag Fcw, the vehicle target driving force Fv*, and the target vehicle speed V* are common to the embodiment and the comparative example. In the comparative example, the target rotation speed Ne* is set without using the comparative rotation speed Neref, that is, when the catalyst warm-up flag Fcw is a value of 1, the requested rotation speed Nerq1 is set to the target rotation speed Ne*, and when the catalyst warm-up flag Fcw is a value of 0, one of the requested rotation speeds Nerq2 and Nerq3 is set to the target rotation speed Ne*. In FIG. 5, the cooling water temperature Tw is higher than the threshold value Twth2 (the required rotation speeds Nerq2 and Nerq3 are smaller than the comparative rotation speed Neref).

[0036] In the comparative example, as shown by the dashed line in FIG. 5, when the catalyst warm-up flag Fcw is switched from value 1 to value 0 during automatic parking (time t11), the target rotation speed Ne* of the engine 22 is reduced from the required rotation speed Nerq1 to one of the required rotation speeds Nerq2 and Nerq3, so that the rotation speed Ne of the engine 22 and the creep driving force Fc based thereon are greatly reduced. At this time, due to a delay in the reduction of the braking force Fb, the vehicle driving force Fv is greatly reduced relative to the vehicle target driving force Fv*, and the vehicle speed V is greatly reduced relative to the target vehicle speed V*, which may cause the driver to feel uncomfortable, such as the vehicle being about to stop before the target parking space 90. In addition, if the braking force Fb is greatly reduced when the vehicle is about to stop before the target parking space 90, the vehicle speed V may increase near the target parking space 90, which may cause the driver to feel uncomfortable.

[0037] In contrast, in the embodiment, as shown by the solid line in FIG. 5, when the catalyst warm-up flag Fcw is switched from value 1 to value 0 during automatic parking (time t11), the target rotation speed Ne* of the engine 22 is reduced from the required rotation speed Nerq1 to a comparative rotation speed Neref that is larger than the required rotation speeds Nerq2 and Nerq3, so that the rotation speed Ne of the engine 22 and the creep driving force Fc based thereon can be suppressed from being significantly reduced. This suppresses the vehicle driving force Fv from being significantly reduced relative to the vehicle target driving force Fv*, and the vehicle speed V from being significantly reduced relative to the target vehicle speed V*. As a result, it is possible to suppress the driver from feeling uncomfortable, such as being about to stop before the target parking space 90. In addition, since there is no need to significantly reduce the braking force Fb thereafter as in the comparative example, it is also possible to suppress the driver from feeling uncomfortable, such as the vehicle speed V increasing near the target parking space 90. In other words, it is preferable to determine and set the comparative rotation speed Neref (predetermined value ΔNeref) in advance through experiments and analyses so as to sufficiently prevent the driver from feeling uncomfortable.

[0038] In the automobile 20 of the embodiment described above, during automatic parking, the maximum value of the requested rotation speed Nerq based on the catalyst warm-up flag Fcw and the air conditioning flag Fac and the comparison rotation speed Neref is set as the target rotation speed Ne* of the engine 22 to control the engine 22. In this case, the requested rotation speed Nerq (request rotation speed Nerq1) when the catalyst warm-up flag Fcw is value 1 is set higher than the requested rotation speed Nerq (request rotation speed Nerq2 or requested rotation speed Nerq3) when the catalyst warm-up flag Fcw is value 0, and the comparison rotation speed Neref is set to be equal to or lower than the requested rotation speed Nerq1 and within a range in which the difference ΔNe from the requested rotation speed Nerq1 is equal to or lower than a predetermined value ΔNeref, and further set to be higher than the requested rotation speeds Nerq2 and Nerq3 in a temperature region in which the cooling water temperature Tw is higher than the threshold value Twth2. As a result, when the warm-up of the catalyst 22c is completed during automatic parking, the target rotation speed Ne* is reduced from the required rotation speed Nerq1 to the larger of the required rotation speed Nerq2 or the required rotation speed Nerq3 and the comparison rotation speed Neref, so that the target rotation speed Ne* is prevented from decreasing significantly, the rotation speed Ne of the engine 22 and therefore the creep driving force Fc based thereon is prevented from decreasing significantly, the vehicle driving force Fv is prevented from decreasing significantly relative to the vehicle target driving force Fv*, and the vehicle speed V is prevented from decreasing significantly relative to the target vehicle speed V*. As a result, it is possible to prevent the driver from feeling uncomfortable, such as being about to stop short of the target parking space 90.

[0039] In the automobile 20 of the embodiment, the required rotation speed Nerq is set based on the catalyst warm-up flag Fcw and the air conditioning flag Fac. However, the required rotation speed Nerq may be set based on the catalyst warm-up flag Fcw without considering the air conditioning flag Fac. In this case, when the catalyst warm-up flag Fcw is 0, the required rotation speed Nerq2 may be used as the required rotation speed Nerq.

[0040] In the automobile 20 of the embodiment, the required rotation speed Nerq is set based on the catalyst warm-up flag Fcw and the air conditioning flag Fac. However, the required rotation speed Nerq may be set based on the air conditioning flag Fac without considering the catalyst warm-up flag Fcw. In this case, the main ECU 30 may execute the target rotation speed setting process of FIG. 6 instead of the target rotation speed setting process of FIG. 3. The target rotation speed setting process of FIG. 6 differs from the target rotation speed setting process of FIG. 3 in that the processes of steps S100 and S110 are replaced with the processes of steps S102 and S112. In the target rotation speed setting process of FIG. 6, the coolant temperature Tw and the air conditioning flag Fac of the engine 22 are input (step S102), a required rotation speed Nerq of the engine 22 is set based on the air conditioning flag Fac and the coolant temperature Tw (step S112), the maximum value of the set required rotation speed Nerq and the comparison rotation speed Neref is set as the target rotation speed Ne* of the engine 22 (step S120), and this routine is terminated.

[0041] FIG. 7 is an explanatory diagram showing an example of a required rotation speed setting map of this modified example. In FIG. 7, the solid line is the required rotation speed Nerq when the air conditioning flag Fac is value 1 (hereinafter referred to as "required rotation speed Nerq11"). The dashed line is the required rotation speed Nerq when the air conditioning flag Fac is value 0 (hereinafter referred to as "required rotation speed Nerq12"). In the example of FIG. 7, the required rotation speeds Nerq11 and Nerq12 are both set to tend to become smaller as the cooling water temperature Tw increases. The required rotation speed Nerq11 is set to be larger than the required rotation speed Nerq12 in the entire temperature range of the cooling water temperature Tw. In FIG. 7, in addition to the required rotation speeds Nerq11 and Nerq12, a comparative rotation speed Neref is also shown. The comparative rotation speed Neref is set within a range that is equal to or less than the required rotation speed Nerq11 and in which the difference ΔNe between the required rotation speed Nerq11 and the required rotation speed Nerq11 is equal to or less than the above-mentioned predetermined value ΔNeref. This comparison speed Neref is further set as a constant value so that it is equal to the required speed Nerq12 when the cooling water temperature Tw is at the threshold value Twth11, is smaller than the required speed Nerq12 in a temperature region where the cooling water temperature Tw is lower than the threshold value Twth11, and is larger than the required speed Nerq12 in a temperature region where the cooling water temperature Tw is higher than the threshold value Twth11.

[0042] By setting the target rotation speed Ne* of the engine 22 in this manner, when the air conditioning of the vehicle interior is terminated, particularly when the cooling water temperature Tw is relatively high, the target rotation speed Ne* is reduced from the required rotation speed Nerq11 to the larger of the required rotation speed Nerq12 and the comparative rotation speed Neref, thereby preventing a large decrease in the target rotation speed Ne*, preventing a large decrease in the rotation speed Ne of the engine 22 and thus the creep driving force Fc based thereon, preventing a large decrease in the vehicle driving force Fv relative to the vehicle target driving force Fv*, and preventing a large decrease in the vehicle speed V relative to the target vehicle speed V*. As a result, it is possible to prevent the driver from feeling uncomfortable, such as being about to stop short of the target parking space 90.

[0043] In the automobile 20 of the embodiment and the modified example, a constant value is used as the comparative rotation speed Neref. However, a variable value based on the coolant temperature Tw may be used as the comparative rotation speed Neref.

[0044] In the automobile 20 of the embodiment and the modified example, the required rotation speed Neac is set in consideration of the air conditioning flag Fac (whether or not the air conditioning of the passenger compartment is being performed by the air conditioner 29). However, if the air conditioner 29 is capable of switching the air volume in multiple stages in addition to being on and off, the required rotation speed Nerq may be set in consideration of the air volume when on and off and when on.

[0045] In the automobile 20 of the embodiment and the modified example, the required rotation speed Nerq is set in consideration of the coolant temperature Tw of the engine 22. However, the required rotation speed Nerq may be set without considering the coolant temperature Tw.

[0046] In the automobile 20 of the embodiment and the modified example, the automatic transmission 24 has a torque converter and a stepped transmission. However, instead of this, the automatic transmission 24 may have a torque converter, a forward / reverse switching mechanism, and a continuously variable transmission.

[0047] In the automobile 20 of the embodiment and the modified example, the engine ECU 23 is used to control the engine 22, the ATECU 25 is used to control the automatic transmission 24, and the brake ECU 27 is used to control the brake device 26. However, all or part of the functions of the engine ECU 23, ATECU 25, and brake ECU 27 may be performed by the main ECU 30.

[0048] In the automobile 20 of the embodiment and the modified example, the power from the engine 22 is output to the drive wheels 28a, 28b via the automatic transmission 24. However, in addition to the configuration of the automobile 20, a motor connected to the engine 22 may be provided.

[0049] The relationship between the main elements of the embodiment and the main elements of the invention described in the section on Means for Solving the Problems will be described below. In the embodiment, the engine 22 corresponds to the "engine", the brake device 26 corresponds to the "braking device", and the engine ECU 23, ATECU 25, brake ECU 27, main ECU 30, etc. correspond to the "control device".

[0050] The correspondence between the main elements of the Examples and the main elements of the invention described in the Summary of the Problem column does not limit the elements of the invention described in the Summary of the Problem column, since the Examples are examples for specifically explaining the mode for implementing the invention described in the Summary of the Problem column. In other words, the interpretation of the invention described in the Summary of the Problem column should be based on the description in that column, and the Examples are merely a specific example of the invention described in the Summary of the Problem column.

[0051] Although the form for carrying out the present invention has been described above using examples, the present invention is not limited to these examples in any way, and it goes without saying that the present invention can be carried out in various forms without departing from the scope of the gist of the present invention. [Industrial Applicability]

[0052] The present invention can be used in the automobile manufacturing industry and the like. [Explanation of symbols]

[0053] 20 automobile, 22 engine, 22a purification device, 22c catalyst, 23 engine ECU, 24 automatic transmission, 25 ATECU, 26 brake device, 27 brake ECU, 28 steering device, 28a, 28b driving wheels, 28c, 28d driven wheels, 28g differential gear, 29 air conditioning device, 29a air conditioning switch, 30 main ECU, 31 CPU, 32 ROM, 33 RAM, 34 flash memory, 40 ignition switch, 41 vehicle speed sensor, 42 wheel speed sensor, 43 acceleration sensor, 44 yaw rate sensor, 45 gradient sensor, 46 accelerator pedal, 47 accelerator pedal position sensor, 48 brake pedal, 49 brake pedal position sensor, 50 shift ECU, 51 shift lever, 52 shift position sensor, 55 surrounding recognition ECU, 56 Surrounding recognition device, 57 automatic driving switch, 58 automatic parking switch, 60 navigation device, 62 main body, 64 GPS antenna, 66 display, 70 display device, 72 communication device, 90 target parking space.

Claims

1. An engine having a catalyst installed in its exhaust system; A braking device that applies a braking force; a control device that controls the engine and the braking device so that, during automatic parking, the vehicle travels based on a vehicle target driving force by adjusting a driving force by idling control of the engine based on a target rotation speed and a braking force by the braking device to move to a target parking position; A vehicle comprising: The control device, during the automatic parking, sets the target rotation speed to a maximum value among a requested rotation speed based on whether or not warming up of the catalyst is necessary and a comparison rotation speed, a first required rotation speed, which is the required rotation speed when the warm-up of the catalyst is required, is set higher than a second required rotation speed, which is the required rotation speed when the warm-up of the catalyst is not required; The comparative rotation speed is set within a range equal to or less than the first required rotation speed and in which a difference between the comparative rotation speed and the first required rotation speed is equal to or less than a predetermined value. car.

2. 2. The vehicle of claim 1, The vehicle further includes an air conditioning device that uses power from the engine to condition the interior of the vehicle. The second required rotation speed is set higher when the vehicle interior air conditioning is being performed than when the vehicle interior air conditioning is not being performed. car.

3. A running engine and A braking device that applies a braking force; an air conditioning device that uses power from the engine to perform air conditioning in a vehicle interior; a control device that controls the engine and the braking device so that, during automatic parking, the vehicle travels based on a vehicle target driving force by adjusting a driving force by idling control of the engine based on a target rotation speed and a braking force by the braking device to move to a target parking position; A vehicle comprising: The control device, during the automatic parking, sets the target rotation speed to a maximum value among a requested rotation speed based on the presence or absence of the vehicle interior air conditioning and a comparison rotation speed, a first required rotation speed, which is the required rotation speed when the vehicle interior air conditioning is performed, is set higher than a second required rotation speed, which is the required rotation speed when the vehicle interior air conditioning is not performed; The comparative rotation speed is set within a range equal to or less than the first required rotation speed and in which a difference between the comparative rotation speed and the first required rotation speed is equal to or less than a predetermined value. car.

4. A vehicle according to any one of claims 1 to 3, the first required rotation speed and the second required rotation speed are set to be smaller when a coolant temperature of the engine is high than when the coolant temperature is low, the comparative rotation speed is set to be higher than the second required rotation speed in at least a part of a temperature range of the cooling water temperature. car.

Images