JP2005119579A - Vehicular automatic cruise control device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a vehicular automatic cruise control device capable of permitting the automatic cruise control start and checking the will of stopping the automatic cruise control. <P>SOLUTION: If a vehicle is in a state that a clutch pedal 52 is regarded to be continuously stepped on for at least a predetermined time from the state of a clutch switch 45, or in a state that the increase in traveling speed per unit time is at least a lower limit, and the vehicle is regarded to be accelerated by the power of an engine 11, or in a state that the magnitude of the change in the traveling speed per unit time is at most the upper limit continuously for at least the predetermined time, and the engine speed is at least the lower limit, and the vehicle is regarded to constantly travel by the power of the engine 11, it is determined that a driver only places his foot on the clutch pedal 52, and the change to the automatic cruise control is permitted. Further, if the vehicle is in a state that the ratio of the engine speed to the traveling speed is not in a predetermined range, and a clutch 21 is regarded to be uncoupled, it is determined that the clutch pedal 52 is stepped in, and it is also determined that the will of stopping the automatic cruise control is expressed. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an auto cruise control device for an automobile.

  A power system for driving driving wheels of an automobile includes an engine as a power source and a transmission that converts the rotational output of the engine into rotational outputs having different rotational speeds. The transmission device switches the transmission gear ratio so that an appropriate rotational output is transmitted to the wheel or the like in accordance with the traveling speed and load, and the transmission gear ratio is switched by, for example, a clutch interposed between the transmission device and the engine. Is cut by a driver's clutch pedal operation, and a gear shift is performed by a transmission.

  On the other hand, the fuel injection amount that defines the engine torque and the rotational speed is usually adjusted by the driver based on the accelerator pedal operation. However, in recent years, the fuel injection amount has been adjusted so that the vehicle is in a predetermined running state. For example, auto-cruise control for adjusting the vehicle speed to be kept constant has been put into practical use. Auto-cruise control is a control method employed in scenes where traffic flows at a substantially constant speed, such as on a motorway.

  The start and stop of the auto-cruise control are switched based on the state of a predetermined operation unit operated by the driver and the state of the clutch pedal. In general, in an auto cruise control apparatus that performs auto cruise control on an engine, the condition that the auto cruise control is started is that the clutch pedal is not depressed, and the clutch pedal is depressed. This is an expression of the driver's intention to stop the auto cruise control. For this reason, a switch for determining a binary value is provided depending on whether the clutch pedal is depressed or not.

  Patent Document 1 listed below cancels auto-cruise by shutting off the power to the actuator for adjusting the throttle opening during auto-cruise so that auto-cruise control is not started and stopped against the intention of the driver. In addition to the microcomputer, which is the usual means for controlling the start and stop of auto-cruise control, the watchdog timer for detecting runaway microcomputers, clutch switch detection signals, brake detection signals, etc. Based on this, the power supply of the actuator can be cut off directly.

In Patent Document 2 below, the pseudo vehicle speed is calculated from the engine speed and the gear ratio, and when the deviation between this and the actual vehicle speed exceeds a predetermined value, this is regarded as the disengagement of the clutch, and the auto cruise control is performed. Something to cancel is proposed. This technology can also be applied to determine whether or not the clutch pedal is depressed as a condition for starting the auto cruise control, and the deviation between the calculated pseudo speed and the actual vehicle speed is different. If it is below the predetermined value, it can be determined that the clutch pedal is not depressed.
Japanese Patent No. 2715606 JP 2003-211998 A

  By the way, some drivers place their feet on the clutch pedal while driving. The clutch has a play in the operation, and the clutch does not become disengaged with the amount of displacement of the clutch pedal as long as the foot is placed on the clutch pedal. However, the clutch switch itself may be sensitive and determined to be in the clutch pedal depression state. In this case, the start of auto-cruise control is not permitted.

  The technique of Patent Document 1 solves a problem in a special situation of microcomputer runaway, and is not necessarily a technique for improving the detection accuracy that the clutch is not depressed.

  Further, although the technique of Patent Document 2 is easily known that the transmission is disconnected without using a clutch switch and can determine that the auto-cruise control should be stopped, the clutch as a condition for starting the auto-cruise control is used. It is not always sufficient as a means for determining whether or not it is established. That is, in order to determine whether or not the clutch pedal is depressed, there is almost no error in the determination if the predetermined value to which the deviation between the calculated pseudo speed and the actual vehicle speed is compared is increased to some extent. However, in order to increase the certainty of determination that the clutch pedal is not depressed, the predetermined value to which the deviation between the pseudo speed and the actual vehicle speed is compared is made extremely small, but the predetermined value is set to be small. Even so, it is extremely difficult to determine that the simulated vehicle speed and the actual vehicle speed are substantially equal due to the influence of the variation in the wheel radius and slip.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide an auto-cruise control device capable of accurately and accurately determining that the clutch pedal has not been depressed.

According to the first aspect of the present invention, the engine is provided in a vehicle having a power system that converts the rotation output of the engine into a predetermined number of rotations by the transmission and transmits it to the wheels, so that the traveling speed of the vehicle is constant. The auto-cruise control device for an automobile that performs auto-cruise control on the condition that the clutch pedal for operating the clutch that connects and disconnects between the engine and the transmission is not depressed, is started. In an auto cruise control device for an automobile that stops the auto cruise control when the clutch pedal is depressed,
First operating state determining means for determining whether or not the state where the clutch pedal is depressed exceeds a preset reference time;
Second operating state determination means for determining whether or not the increase amount per unit time of the traveling speed is equal to or higher than a preset lower limit value;
It is assumed that the auto cruise control is allowed on condition that both the first and second driving state determination means are positively determined.

  Even if the driver steps on the clutch pedal, the state in which the clutch pedal is depressed continues beyond the time required for normal clutch pedal operation as long as the driver is just stepping on the foot. If the amount of change in the traveling speed per unit time exceeds a natural acceleration due to a downhill or the like and takes a large value, it can be said that the vehicle is accelerating due to an increase in the output power of the engine. Therefore, both determinations of the first and second driving state determination means are affirmed. In such a driving state, there is a high probability that the driver is just putting a foot on the clutch pedal. It is possible to accurately determine that the operation state is allowed to start.

According to a second aspect of the present invention, the engine is provided in a vehicle having a power system that converts the rotational output of the engine into a predetermined number of rotations by a transmission and transmits it to the wheels, so that the traveling speed of the vehicle is constant. The auto-cruise control device for an automobile that performs auto-cruise control on the condition that the clutch pedal for operating the clutch that connects / disconnects between the engine and the transmission is not depressed. In an auto cruise control device for an automobile that stops the auto cruise control when the clutch pedal is depressed,
First operating state determining means for determining whether or not the state where the clutch pedal is depressed exceeds a preset reference time;
It is determined whether or not the amount of change per unit time of the traveling speed exceeds a preset reference time and is less than or equal to a preset upper limit value and the rotational speed of the engine rotation output is equal to or greater than a preset lower limit value. Second operating state determination means,
It is assumed that the auto cruise control is allowed on condition that both the first and second driving state determination means are positively determined.

  Even if the driver steps on the clutch pedal, the state in which the clutch pedal is depressed continues beyond the time required for normal clutch pedal operation as long as the driver is just stepping on the foot. If the amount of change in the running speed per unit time is only a fluctuation that is recognized during steady running, and the state continues for a certain period of time and the engine rotation output has a certain number of revolutions, this operation It can be determined that the vehicle is in steady running by the output power of the engine. Therefore, both determinations of the first and second driving state determination means are affirmed. In such a driving state, there is a high probability that the driver is just putting a foot on the clutch pedal. It is possible to accurately determine that the operation state is allowed to start.

According to a third aspect of the present invention, in the configuration of the first or second aspect of the present invention, a third method for determining whether or not the ratio between the rotational speed of the engine rotational output and the vehicle speed is within a predetermined range. Equipped with a driving state judging means of
The auto-cruise control is stopped on the condition that the third driving state determination means is negatively determined.

  In a state in which the clutch is coupled between the engine and the transmission, the ratio between the rotational speed of the engine rotation output and the traveling speed is a constant ratio defined by the gear ratio of the transmission. The driving state in which this ratio has changed beyond the error range due to variations in wheel radius, etc. is likely to cause the clutch pedal to shift to the depressed state, not the footrest state, and driving that should stop auto-cruise control It is possible to accurately determine that it is in a state.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 shows an automobile power system to which an auto cruise control device of the present invention is applied. The rotation output taken out from the crankshaft 111 of the engine 11 is transmitted to the drive wheels 31 and 32 via the power transmission device 2.

  The power transmission device 2 includes a clutch 21, a transmission 22 that is a transmission, a propeller shaft 23, a differential 24, and the like from the engine 11 side. A plurality of gear positions can be selected for the transmission 22. Normally, when the driver depresses the clutch pedal 52, the clutch 21 is disconnected and the engine 11 and the transmission 22 are disconnected, and the driver operates the shift lever. A gear shift is made. Then, the rotational output of the engine 11 is converted into a rotational output having a different rotational speed according to the gear ratio.

  Various controls such as fuel injection control are performed by the ECU 41. The ECU 41 includes, for example, a microcomputer including a CPU, a RAM, and a ROM, an input / output circuit, and the like. In order to execute the control, the ECU 41 includes sensors 42 for detecting the state (operating state) of each part of the engine. Signals from 43, 44 and 45 are input. As such sensors, an accelerator opening sensor 42 for detecting the opening of the throttle valve 12, an engine speed sensor 43 for detecting the rotational speed of the engine 11 (hereinafter referred to as the engine speed as appropriate), A vehicle speed sensor 44 that detects the traveling speed, a clutch switch 45 that detects the state of the clutch pedal 52, and the like are provided. As described in the prior art, the clutch switch 45 is a switch that is turned on only by the driver placing his / her foot on the clutch pedal 52. In addition to these sensors, although not shown, sensors such as an A / F sensor attached to a general engine are provided.

  In the ECU 41, the fuel injection amount is basically calculated by using the depression amount of the accelerator pedal 51 that the driver steps on as a torque request of the driver. Specifically, it is set according to the map with the accelerator opening and the engine speed as inputs. The fuel injection amount command value is set by another method during auto-cruise control. Auto-cruise control is a control that is effective on the condition that the operation unit provided on the instrument panel of the vehicle is switched to the cruise mode side by the driver's operation, and the detected vehicle speed is set by the driver. The injection amount command value is set so that the required vehicle speed is obtained.

  The switching between the start and stop of the auto cruise control will be described. The start of the auto-cruise control is conditional on the operation unit being switched to the cruise mode side as described above, but as a precondition, the clutch pedal 52 is not in the depressed state. The case where the clutch pedal 52 is not in the depressed state corresponds to a state in which the driver has only left his / her foot on the clutch pedal 52 in addition to a state in which the driver removes his / her foot from the clutch pedal 52. The former is known from the fact that the clutch switch 45 is off. The determination as to whether or not the latter is a feature of the present invention will be described with reference to FIG. FIG. 2 shows the control executed by the microcomputer of the ECU 41, and shows a determination as to whether or not the driver is simply placing a foot on the clutch pedal 52 (hereinafter simply referred to as a clutch pedal foot determination). ing.

  Steps S101 and S102 are processing as first operating state determination means. In step S101, it is determined whether XCL = 1. XCL is a flag that is set when the clutch switch 45 is on, and is reset again when it is off. XCL is updated at regular intervals by a timer interrupt. If XCL = 1, it means that the clutch pedal 52 is displaced to the extent that the clutch switch 45 is turned on at least when the driver steps on the clutch pedal 52.

  If a negative determination is made in step S101, it is determined in step S106 that the clutch pedal 52 is not placed (hereinafter, referred to as a clutch pedal non-footed state as appropriate), and the process returns to step S101.

  If an affirmative determination is made in step S101, it is determined in step S102 whether or not the duration time during which the driver steps on the clutch pedal 52 exceeds the mask time. If a negative determination is made, the process returns from step S106 to step S101. If an affirmative determination is made, the process proceeds to step S103. The duration that the clutch pedal 52 is depressed by the driver is a duration that is XCL = 1. Specifically, for example, the number of times that step S101 is continuously affirmed is counted, and the number of times Given. Then, it is compared with a predetermined number of times corresponding to the mask time.

  Step S103 is a process as a second operating state determination means. In step S103, the previous travel speed is subtracted from the current travel speed, and the calculation result ΔSPD is compared with the lower limit value α to determine whether ΔSPD exceeds α. The current traveling speed, that is, the latest traveling speed is taken in at a predetermined cycle by a timer interrupt. Since the travel speed capturing period is constant, ΔSPD is the amount of increase in travel speed per unit time at the present time.

  If ΔSPD does not reach the lower limit α and step S103 is affirmatively determined, the process proceeds to step S105, where the driver's foot is placed on the clutch pedal 52 (hereinafter referred to as the clutch pedal footing state as appropriate). Authorize. After executing step S105, the process returns to step S101.

  If a negative determination is made in step S103, the process proceeds to step S104. Step S104 is a process as a second operating state determination unit different from step S103. In step S104, it is determined whether or not the following condition is satisfied. The condition is that the magnitude | ΔSPD | of the ΔSPD is not more than the upper limit value β, the duration of the state exceeds γ, and the engine speed NE exceeds the lower limit value ε. . The mask times, α, β, γ, and ε are preset and stored in the ROM together with the control program.

  If a positive determination is made in step S104, the clutch pedal footing state is recognized (step S105).

  When a negative determination is made in step S104, the process returns from step S106 to step S101.

  Thus, in addition to affirmative determination in step S102, if a positive determination is made in step S103 or step S104, the clutch pedal footrest state is recognized.

  Even if the clutch pedal 52 is stepped on, as long as the driver is merely stepping on, the state in which the clutch pedal is stepped on continues beyond the time required for normal clutch pedal 52 operation during gear shifting. . If the amount of change in the traveling speed per unit time exceeds a natural acceleration due to a downhill or the like and takes a large value, it is an acceleration due to an increase in the output power of the engine 11. Accordingly, both determinations in steps S102 and S103 are affirmatively determined. In such a driving state, there is a high probability that the driver is just putting a foot on the clutch pedal 52, and automatic cruise control can be permitted. It can be accurately determined that the vehicle is in an operating state. Because of the abnormality, the mask time is set in consideration of the time required for normal clutch pedal 52 operation during gear shifting. α is set in consideration of acceleration that exceeds the range of natural acceleration due to a downhill or the like and can be regarded as acceleration due to an increase in output power of the engine 11.

  In addition to the fact that the state where the clutch pedal 52 is depressed continues beyond the time required for normal operation of the clutch pedal 52, the amount of change in the traveling speed per unit time is recognized during steady driving. If the state continues for a certain period of time and the engine speed is at a certain level, it can be determined that the vehicle is in steady running by the output power of the engine 11. Accordingly, both determinations in steps S102 and S104 are affirmed. In such a driving state, there is a high probability that the driver is just putting a foot on the clutch pedal 52, and automatic cruise control can be permitted. It can be accurately determined that the vehicle is in an operating state. From the above, β is set in consideration of the magnitude recognized as the fluctuation of the running speed recognized during steady running. γ is set to such an extent that it can be inferred that the state in which | ΔSPD | is equal to or less than the upper limit value β is stable and the amount of change in travel speed per unit time is kept small. ε is set in consideration of steady travel by the output power of the engine 11.

  FIG. 3 shows the relationship between the depression amount of the clutch pedal 52 (in the figure, the depression amount of the clutch pedal) and the transmission rate of the clutch 21. The depression amount of the clutch pedal 52 is from 0 to a predetermined depression amount. The transmission rate is substantially constant. Further, when the pedal is stepped on, a so-called half-clutch region in which the transmission rate decreases in accordance with the stepping amount reaches the stepping amount that results in a disconnected state. This auto-cruise control device detects a state in which the clutch 21 almost reliably transmits the rotational output of the engine 11 to the transmission 22, and at this time, it can be regarded as a simple footrest on the clutch pedal 52. It has become.

  Steps S103 and S104 are for determining independent operating states as described above, and the execution order may be reversed.

  As described above, the ECU 41 determines whether or not to allow the start of the auto-cruise control based on whether or not the clutch switch 45 is recognized as the clutch footrest state together with the state of the clutch switch 45 (XCL). That is, when the driver's foot is away from the clutch pedal 52 and XCL = 0, the start of auto-cruise control is permitted. Moreover, if there is footrest certification, the start of auto-cruise control is permitted.

  Next, it is shown whether or not the clutch pedal 52 is being depressed (hereinafter simply referred to as clutch depression determination). In step S201, it is determined whether or not the wheels 31, 32 are slipping. The determination of whether or not the vehicle is slipping can be performed by a known method such as a determination based on the rotational speeds of the driven wheels and drive wheels 31 and 32 (not shown).

  If the wheels 31 and 32 are slipping and the determination in step S201 is affirmative, it is determined in step S204 that the clutch pedal 52 is not depressed (hereinafter referred to as the clutch pedal non-depressed state as appropriate), and the process proceeds to step S201. Return.

  If a negative determination is made in step S201, the process proceeds to step S202. Step S202 is a process as a third operating state determination unit. In step S202, it is determined whether or not the ratio NE / SPD between the current engine speed NE and the traveling speed SPD is within a predetermined range, that is, whether A <NE / SPD <B. A and B are preset and stored in the ROM. The NE / SPD is defined by the gear ratio of the transmission 22 and the differential gear 24 and the wheel radius, and does not vary greatly as long as the clutch 21 is in a state before being disengaged. When adjusting the engine speed to the gear after the shift at the time of gear shift, NE / SPD is considered to be abnormally small or large beyond the error range due to variations in the wheel radius, etc. Is set to a value that can be regarded as a state in which the clutch 21 exhibits a transmission rate of a certain level or more.

  If a positive determination is made in step S202, the process returns to step S201. If a negative determination is made in step S202, it is determined in step S203 that the clutch pedal 52 is being depressed (hereinafter referred to as a clutch pedal depression state as appropriate). . After step S203 is executed, the process returns to step S201.

  In the state where the clutch 21 is coupled between the engine 11 and the transmission 22 as described above, the NE / SPD is substantially constant, and the operating state in which this has changed beyond the error range due to variations in wheel radius and the like is The probability that the clutch pedal has shifted to the depressed state rather than the footrest state is high, and it can be accurately determined that the driving state is to stop the automatic cruise control. The ECU 41 stops the auto-cruise control when it is recognized that the clutch pedal is depressed.

  FIG. 5A, FIG. 5B, FIG. 5C, and FIG. 5D show the operating state of the present auto cruise control device. In the example of FIG. 5A showing the start of auto-cruise control (simply auto-cruise in the figure), even if the clutch pedal 52 is depressed, if the driver selects the auto-cruise mode, the clutch pedal footrest state If it is certified, auto cruise control is started. Note that, in the example of FIG. 5B in which the clutch pedal 52 is depressed during execution of auto-cruise control, the auto-cruise control is stopped by determining that the clutch pedal is depressed. In the example of FIG. 5 (C) in which the footrest is stopped and the foot is released from the clutch pedal 52 during execution of auto-cruise control, when the foot is released from the clutch pedal 52 (XCL = 0), the clutch pedal footing state is recognized. Canceled. Auto cruise control continues. Further, in the example of FIG. 5D showing a case where the foot is placed from the state where the foot is released from the clutch pedal 52 during execution of the auto cruise control, XCL = 1 is set when the clutch pedal 52 is depressed. Since it is not recognized that the clutch pedal is depressed, the auto-cruise control continues.

  As described above, according to the present automatic cruise control device, it is possible to accurately determine the driving state that allows the start of the automatic cruise control and the driving state that can be regarded as an expression of the intention to stop, and appropriately start the automatic cruise control and Stop switching can be performed.

It is a block diagram centering on the power system of the motor vehicle to which the auto cruise control device of the present invention is applied. It is a 1st flowchart which shows the control performed by ECU which comprises the said auto cruise control apparatus. It is a graph which shows the operating characteristic of the clutch which comprises the said motive power system. It is a 2nd flowchart which shows the control performed by ECU which comprises the said auto cruise control apparatus. (A), (B), (C), (D) are timing charts showing the operating state of the auto cruise control device.

Explanation of symbols

11 Engine 111 Crankshaft 12 Throttle valve 2 Power transmission device 21 Clutch 22 Transmission (transmission)
23 Propeller shaft 24 Differential gear 31, 32 Drive wheel 41 ECU (Operating state judging means)
42 Accelerator opening sensor 43 Rotational speed sensor 44 Vehicle speed sensor 45 Clutch switch

Claims (3)

An automobile having a power system that converts the rotational output of the engine into a predetermined number of revolutions by a transmission and transmits it to the wheels, and performs auto-cruise control on the engine so that the running speed of the automobile is constant The auto-cruise control device is configured to allow the start of the auto-cruise control on the condition that the clutch pedal for operating the clutch that connects and disconnects between the engine and the transmission is not depressed, and the clutch pedal is depressed In an automobile auto-cruise control device that stops the auto-cruise control when rare,
First operating state determining means for determining whether or not the state where the clutch pedal is depressed exceeds a preset reference time;
Second operating state determining means for determining whether or not the increase amount per unit time of the traveling speed is equal to or higher than a preset lower limit value;
An auto-cruise control device, wherein the auto-cruise control is allowed on condition that both the first and second driving state determination means are positively determined. An automobile having a power system that converts the rotational output of the engine into a predetermined number of revolutions by a transmission and transmits it to the wheels, and performs auto-cruise control on the engine so that the running speed of the automobile is constant The auto-cruise control device is configured to allow the start of the auto-cruise control on the condition that the clutch pedal for operating the clutch that connects and disconnects between the engine and the transmission is not depressed, and the clutch pedal is depressed In an automobile auto-cruise control device that stops the auto-cruise control when rare,
First operating state determining means for determining whether or not the state where the clutch pedal is depressed exceeds a preset reference time;
It is determined whether or not the amount of change per unit time of the traveling speed exceeds a preset reference time and is less than or equal to a preset upper limit value and the rotational speed of the engine rotation output is equal to or greater than a preset lower limit value. Second operating state determining means,
An auto-cruise control device for an automobile, wherein the auto-cruise control is allowed on condition that both the first and second driving state determination means are positively determined. 3. The auto-cruise control device for an automobile according to claim 1 or 2, wherein a third operation for determining whether a ratio between the rotational speed of the engine rotation output and the speed of the automobile is within a predetermined range set in advance. Equipped with state determination means,
An auto-cruise control device for an automobile in which the auto-cruise control is stopped on condition that the third driving state judgment means is negatively judged.

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