JP2005263098A - Automatic cruise control device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an automatic cruise control device suitable for controlling a vehicle speed while properly holding an inter-vehicle distance with a preceding car. <P>SOLUTION: This automatic cruise control device is arranged in a vehicle having a main brake and a plurality of kinds of auxiliary brakes; and is provided with a target deceleration calculating means for arithmetically operating target deceleration to one's own vehicle from the inter-vehicle distance with the preceding car and a relative speed with the preceding car, an auxiliary brake control means for successively operating the plurality of kinds of auxiliary brakes in order from an auxiliary brake small in deceleration in response to the calculated target deceleration, and a main brake control means for operating the main brake by chamber pressure corresponding to a deceleration difference between the total deceleration and target deceleration when the total deceleration by the whole operations of the plurality of kinds of auxiliary brakes is less than the target deceleration. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an auto-cruise control device suitable for controlling the vehicle speed while appropriately maintaining the inter-vehicle distance from a preceding vehicle.

  Auto-cruise control in automobiles is constant-speed traveling control that realizes constant-speed traveling according to the set vehicle speed. However, when there is no preceding vehicle ahead of the host vehicle, the above-mentioned constant-speed traveling control is performed and within a predetermined distance range. Some vehicles also include an inter-vehicle distance control that controls the vehicle speed so as to keep the inter-vehicle distance from the preceding vehicle constant when there is a preceding vehicle. In such auto-cruise control, basically, for example, a target accelerator opening is obtained according to the own vehicle speed detected by a vehicle speed sensor, and the fuel injection amount for the engine is increased or decreased according to the target accelerator opening. At the same time, it is executed while appropriately decelerating the auxiliary brake. By the way, the inter-vehicle distance control uses an inter-vehicle distance sensor such as a laser radar or a millimeter wave radar, or obtains the inter-vehicle distance and relative speed from the preceding vehicle using a camera and based on these information. This is done while appropriately operating the auxiliary brakes equipped with.

For the auxiliary brake, an engine brake that uses the rotational load of the engine, an exhaust brake that uses the exhaust pressure by narrowing the exhaust pipe, and a specific valve (third valve) in the engine are opened from the compression stroke to the exhaust stroke. There are a compression pressure release engine brake using a negative work amount generated by this, a fluid type retarder that adjusts a flow of fluid by changing a blade angle of a stator in a fluid coupling, and an electromagnetic type retarder. The above-mentioned inter-vehicle distance control is executed by combining these plural types of auxiliary brakes as appropriate according to, for example, the transmission gear speed, vehicle speed, and the like (see, for example, Patent Document 1).
Japanese Patent No. 3158924

  However, there is a limit to the braking force of each auxiliary brake described above. For this reason, in the conventional inter-vehicle distance control, when the preceding vehicle decelerates, when another vehicle has entered the closest distance in front of the host vehicle, or when driving on a steep downhill road However, sufficient deceleration cannot be obtained even if all of the above-described plural types of auxiliary brakes are operated. As a result, there is a possibility that an appropriate vehicle speed cannot be maintained and a sufficient inter-vehicle distance cannot be maintained. Then, since the inter-vehicle distance control does not function normally, the brake operation by the driver becomes indispensable, and the role of the auto cruise control is impaired.

  The present invention has been made in consideration of such circumstances, and the purpose of the present invention is the same as the preceding vehicle even when the preceding vehicle decelerates or when another vehicle interrupts at a close distance in front of the host vehicle. Another object of the present invention is to provide an auto-cruise control device suitable for controlling the vehicle speed while properly maintaining the inter-vehicle distance.

  The present invention controls the vehicle speed by appropriately combining a plurality of types of auxiliary brakes according to the vehicle speed and the transmission gear stage, thereby controlling the inter-vehicle distance with the preceding vehicle. Obtain the required deceleration (target deceleration) to keep the distance between the vehicle and the preceding vehicle constant, and obtain the braking force necessary to obtain this deceleration (target deceleration) from the brake mechanism equipped on the vehicle. In this way, attention is paid to the fact that the brake operation by the driver becomes unnecessary.

Therefore, in order to achieve the above-described object, the auto-cruise control device according to the present invention performs inter-vehicle distance control that is provided in a vehicle equipped with a main brake and a plurality of types of auxiliary brakes and maintains a constant inter-vehicle distance from the preceding vehicle. Therefore,
<a> Target deceleration calculation means for calculating a target deceleration for the host vehicle from the inter-vehicle distance detected with the inter-vehicle distance sensor or the like and the relative speed with the preceding vehicle;
<b> Auxiliary brake control means for sequentially operating the plurality of types of auxiliary brakes according to the calculated target deceleration, in order from the auxiliary brake having the smallest deceleration,
<c> When the total deceleration due to all the operations of the plurality of types of auxiliary brakes is less than the target deceleration, the main brake is operated according to the difference in deceleration between the total deceleration and the target deceleration And a main brake control means.

  That is, the auto-cruise control device according to the present invention calculates a target deceleration with respect to the host vehicle from the inter-vehicle distance and relative speed with the preceding vehicle, and sets a plurality of types of auxiliary brakes according to the target deceleration. The brakes are sequentially operated in order from the brake, specifically the engine brake, the exhaust brake, the compression pressure release engine brake, and the retarder, and when the total deceleration due to all the operations of these auxiliary brakes is less than the target deceleration, The target deceleration is reliably obtained by operating the main brake in accordance with the deceleration difference between the total deceleration and the target deceleration.

  Preferably, the main brake control means sets a chamber pressure for determining a braking force (deceleration) of the main brake according to, for example, claim 2 according to a deceleration difference between the total deceleration and the target deceleration. The chamber pressure is determined by instructing an electronically controlled main brake mechanism (EBS) to operate the main brake. In other words, the operation of the auxiliary brake described above is controlled on / off according to the target deceleration, but the braking force of the main brake is finely controlled by controlling the chamber pressure according to the above-described deceleration difference. It is characterized by variable control.

An auto cruise control device according to the present invention is further provided as described in claim 3.
<d> An interrupt determination means for determining whether or not there is a sudden change in the inter-vehicle distance with the preceding vehicle, and detecting as an interrupt of another vehicle ahead of the host vehicle when the inter-vehicle distance decreases abruptly;
<e> It is characterized by comprising target deceleration correction means for gradually increasing the target deceleration when this interruption is detected.

In other words, when another vehicle interrupts in front of the host vehicle, the target deceleration that has been used up to that point can be used without promptly changing the target deceleration of the inter-vehicle distance control as a new preceding vehicle. It is characterized by preventing sudden fluctuations in inter-vehicle distance control by gradually changing the speed.
Incidentally, the target deceleration correction means, when correcting the target deceleration every predetermined cycle, for example, as described in claim 4, keeps the previous target deceleration constant up to a preset deceleration limit value. The current target deceleration rate is determined by increasing the ratio.

  According to the auto-cruise control device including the auxiliary brake control means and the main brake control means described above, the target deceleration is set according to the target deceleration for the host vehicle obtained from the inter-vehicle distance and the relative speed with the preceding vehicle. Since the vehicle can be decelerated and controlled by determining the braking force required for the auxiliary brake and further the main brake, the driver brakes due to insufficient braking force due to the auxiliary brake as in the past. There is no need. Therefore, the function of inter-vehicle distance control can be sufficiently exhibited. In other words, the control range for the inter-vehicle distance control can be expanded, and comfortable auto-cruise control can be realized.

  Further, according to the auto cruise control device further provided with the interrupt determination means and the target deceleration correction means described above, the target deceleration described above is gradually increased even when another vehicle suddenly interrupts at a close distance in front of the host vehicle. The inter-vehicle distance control is executed while the target deceleration changes suddenly, so that it is possible to prevent the occurrence of problems such as sudden braking, and the preceding vehicle subject to the inter-vehicle distance control can be smoothly It becomes possible to change to. Therefore, even if there is an abrupt interruption of another vehicle, the inter-vehicle distance control reacts excessively, and this brings about an effect such as not causing a problem that the driving comfort is impaired.

Hereinafter, an automatic cruise control device according to an embodiment of the present invention will be described with reference to the drawings.
The inter-vehicle distance control in this auto-cruise control device is such that the vehicle speed is controlled so that the inter-vehicle distance L with the preceding vehicle B traveling in front of the own vehicle (truck) A is kept constant as shown in FIG. It is something to control. This inter-vehicle distance control is executed while detecting the host vehicle speed using a vehicle speed sensor and detecting the inter-vehicle distance L and the relative speed with respect to the preceding vehicle B using, for example, a laser radar or a millimeter wave radar. In the above-described auto cruise control device, when the preceding vehicle B does not exist in front of the host vehicle A, constant speed traveling control is executed exclusively to keep the host vehicle speed constant based on the set vehicle speed.

  The above-mentioned inter-vehicle distance control and constant-speed traveling control basically obtain target accelerator opening information (pseudo accelerator opening) from the own vehicle speed, the inter-vehicle distance, the relative speed with the preceding vehicle, etc. This is realized by determining the fuel injection amount for the engine in accordance with the information and controlling the own vehicle speed, and operating a plurality of types of auxiliary brakes included in the own vehicle A to decelerate the own vehicle A. The auxiliary brake is generated, for example, by opening an engine brake using an engine rotation load, an exhaust brake using exhaust pressure, or a specific valve (third valve) provided in the engine from the compression stroke to the exhaust stroke. It consists of a compression pressure release engine brake using negative work, and a fluid type retarder and an electromagnetic type retarder that adjust the flow of fluid by changing the blade angle of the stator in the fluid coupling.

  The auto-cruise control device according to the present invention actively uses an electronic main brake of the own vehicle A in addition to the above-described auxiliary brake, and particularly from the inter-vehicle distance and the relative speed with the preceding vehicle B. According to the required target deceleration, the auxiliary brake necessary for obtaining the target deceleration and the braking force of the main brake are further determined to control the deceleration of the own vehicle A.

  Specifically, according to the present invention, the deceleration obtained when each of the plurality of types of auxiliary brakes is operated is different for each type of auxiliary brake, and the deceleration obtained by the operation of the main brake is determined by the chamber pressure. We focus on the fact that it can be varied. Therefore, in the automatic cruise control device according to the present invention, the plurality of types of auxiliary brakes are sequentially operated in order from the smallest deceleration according to the target deceleration, and even if all the auxiliary brakes are activated, the target deceleration is achieved. Is not obtained, the target brake is operated by generating the chamber pressure corresponding to the deceleration difference between the total deceleration due to all the operations of the auxiliary brake and the target deceleration, and operating the main brake. I'm trying to get speed.

  The main brake will be briefly described with reference to FIG. In this main brake, the compressed air (air pressure) obtained in the air tank 1 is basically incorporated into the front and rear, left and right wheels (not shown) via the control valve 2 (2FL, 2FR, 2RL, 2RR). The brake chamber 3 (3FL, 3FR, 3RLA, 3RRA, 3RLB, 3RRB) is applied to each wheel to apply braking force to each wheel. In particular, in the electronically controlled main brake, the operation of each control valve 2 is controlled by an electric control signal from a brake control computer (EBS-ECU) 5 that detects the amount of depression of the brake pedal mechanism 4 and the like. By doing so, the braking force (chamber pressure) is controlled.

  In this electronically controlled main brake, even if a failure occurs in the electrical control of each control valve 2 due to a failure of the ECU, the brake pedal mechanism 4 has a stepping pressure operation amount. A corresponding chamber pressure is applied to each brake chamber 3 via the control valve 2. That is, an air supply system that supplies compressed air from the air tank 1 to the brake chambers 3 via the brake pedal mechanism 4 is provided in addition to the electronically controlled air supply system described above.

  The main brake control in the auto-cruise control according to the present invention is, as will be described later, from an auto cools control computer (ACC-ECU) 6 to a deceleration control from the brake control computer (EBS-ECU) 5. This is achieved by providing the required target chamber pressure and externally supplying the computer (EBS-ECU) 5 independently of the operation of the brake mechanism 4 described above.

  Now, the automatic cruise control apparatus that executes such control is schematically configured as shown in FIG. Note that the auto cruise control device having the functional block configuration shown in FIG. 3 may be realized as software on a computer (ECU) responsible for auto cruise control. This auto-cruise control device includes information on the vehicle speed detected by the vehicle speed sensor, information on the set vehicle speed and the set inter-vehicle distance given by an auto-cruise instruction operation, and a preceding vehicle obtained from an inter-vehicle distance sensor such as a millimeter wave radar. Information on the inter-vehicle distance with B and the relative speed are taken as input data, and the control operation is executed.

  When the auto-cruise control is not executed, the auto-cruise control switch 11 is switched to the OFF (OFF) side, so that it is actually obtained from an accelerator opening sensor attached to an accelerator pedal (not shown). Information on the accelerator opening operated by the driver is given to the engine ECU 12. Then, the fuel injection amount is determined based on the accelerator opening information, whereby the vehicle speed or the engine torque is controlled. On the other hand, when executing the auto-cruise control, the auto-cruise control switch 11 is switched to the on (ON) side, and the accelerator opening degree increase / decrease control unit 13 is controlled based on the vehicle speed or the like as described below. The obtained pseudo accelerator opening degree increase / decrease information is provided to the engine ECU 12 via the adder 14. The adder 14 adds the pseudo accelerator opening degree increase / decrease information output from the accelerator opening degree increase / decrease control unit 13 to the previous accelerator opening degree information given to the engine ECU 12 to the engine ECU 12. It plays a role of obtaining current accelerator opening information (pseudo accelerator opening information) to be given.

  Here, the accelerator opening increase / decrease control unit 13 will be described. When the preceding vehicle B does not exist, the accelerator opening increase / decrease control unit 13 determines the difference (vehicle speed deviation) between the own vehicle speed obtained using the differentiator 15 and the set vehicle speed. ), And a value obtained by differentiating the vehicle speed deviation through the differentiator 16 (rate of change in vehicle speed deviation), and the pseudo accelerator opening degree is set so that the vehicle speed deviation is 0 (zero) according to the information. The amount of increase / decrease (accelerator position increase / decrease information) is obtained. Specifically, when the host vehicle speed exceeds the set vehicle speed, information is output to decrease the aforementioned pseudo accelerator opening, and conversely, when the host vehicle speed is less than the set vehicle speed, the pseudo accelerator opening is increased. Information is output. Then, the accelerator opening degree increase / decrease information is given to the engine ECU 12 via the adder 14 described above. As described above, the fuel injection amount is determined, and constant speed running control is realized.

  On the other hand, when the preceding vehicle B exists, the accelerator opening degree increase / decrease control unit 13 uses the target vehicle speed obtained by the vehicle speed increase / decrease control unit 17 based on the relative vehicle speed and the inter-vehicle distance instead of the set vehicle speed. That control is being executed. Specifically, the difference (vehicle speed deviation) between the target vehicle speed obtained by the vehicle speed increase / decrease control unit 17 and the host vehicle speed is calculated by the differentiator 15, and the vehicle speed deviation is reduced to 0 according to the vehicle speed deviation and its differential value. The above-described pseudo increase / decrease amount of the accelerator opening (accelerator opening increase / decrease information) is obtained so as to be (zero). The accelerator opening / closing information is input to the engine ECU 12, and the above-described constant speed traveling control and inter-vehicle distance control are performed.

  The information on the target vehicle speed obtained by the vehicle speed increase / decrease control unit 17 is given to the target deceleration control unit 18 at the same time. The target deceleration control unit 18 needs to apply braking to the host vehicle A according to the inter-vehicle distance deviation obtained by the calculator 19 according to the set inter-vehicle distance and the inter-vehicle distance and the target vehicle speed obtained by the vehicle speed increase / decrease control unit 17. It plays the role of judging whether or not. Specifically, as described above, the fuel injection amount is determined based on the pseudo accelerator opening, and it is determined whether or not the inter-vehicle distance can be kept constant only by controlling the vehicle speed or the engine torque. If the inter-vehicle distance cannot be kept constant only by the vehicle speed control, the target vehicle speed and the inter-vehicle distance deviation are obtained based on the above-described target vehicle speed and inter-vehicle distance deviation information, which are specifically obtained from these information according to the inter-vehicle distance and relative speed. The deceleration f0 is calculated, and the information (target deceleration f0) is given to the target braking force calculator 20 to execute the brake control.

  The target braking force calculation unit 20 calculates a braking force (target braking force) necessary for obtaining the above-described target deceleration f0 from the motion characteristics of the vehicle A and the like. The target braking force is applied to the auxiliary brake control unit 21, and the plurality of types of auxiliary brakes 22a to 22n included in the vehicle A are sequentially driven as will be described later. The information on the target braking force is given to the auxiliary brake driving force calculating unit 23, and the total sum (total deceleration) of the braking force obtained when all the auxiliary brakes 22a to 22n are operated is calculated. ing. The difference between the braking force information obtained by the operation of the auxiliary brakes 22a to 22n and the target braking force obtained by the target braking force calculation unit 20 is not limited to the braking force obtained by the operation of the auxiliary brakes 22a to 22n. An insufficiency of the target braking force that cannot be satisfied is obtained by the subtractor 24.

  The target chamber pressure calculation unit 25 calculates the chamber pressure for generating the insufficient braking force by the main brake 26 according to the information on the insufficient braking force obtained by the subtractor 24, and obtains the information on the chamber pressure. The main brake 26 is applied to the above-described ECU 5 to operate the main brake 26. That is, the target chamber pressure calculation unit 25 is driven when the above-described target deceleration cannot be achieved only by operating the auxiliary brakes 22a to 22n, and an insufficient deceleration is obtained by operating the main brake 26. The chamber pressure applied to the main brake 26 is obtained. The deceleration control necessary for performing the above-mentioned inter-vehicle distance control is performed by the operation control of the auxiliary brakes 22a to 22n and the operation control of the main brake 26.

  The above-described inter-vehicle distance control stably captures the preceding vehicle B and keeps the inter-vehicle distance from the preceding vehicle B constant based on the inter-vehicle distance and the relative vehicle speed. When another vehicle interrupts the closest distance, the interrupt determination unit 27 determines the interrupt. The interrupt determination unit 27 monitors the above-described inter-vehicle distance, and determines that this is determined as an interrupt of another vehicle when a short inter-vehicle distance is detected as compared with the inter-vehicle distance obtained so far. When such an interrupt is detected, the interrupt determination unit 27 corrects the target deceleration control unit 18 to gradually increase the target deceleration required by the target deceleration 18.

  Specifically, the interrupt determination unit 18 obtains a deceleration increase amount by multiplying a previous target deceleration obtained every predetermined control cycle by a predetermined coefficient when the occurrence of an interrupt is detected, and this deceleration increase amount. Is the previously set target deceleration, and the target deceleration is gradually increased until the target deceleration reaches a preset deceleration limit value (limit value). The target deceleration control at the time of detecting an interrupt avoids a situation in which a large braking force is suddenly applied, and smoothes the deceleration so that the inter-vehicle distance is gradually secured to the other vehicle that has been interrupted. Distance control is executed.

  Here, the deceleration control using the plurality of types of auxiliary brakes 22a to 22n and the main brake 26 will be described in more detail. This deceleration control is executed according to the procedure shown in FIG. 4, for example. The deceleration control is started by first obtaining the target deceleration f0 by the target deceleration control unit 18 according to the inter-vehicle distance from the preceding vehicle A and the relative speed as described above [step S1]. Then, under the control of the auxiliary brake controller 21, the preset determination thresholds h0, h1, to hn and the target deceleration f0 are respectively compared, and according to the comparison result, a plurality of types of auxiliary brakes 22a to 22n are determined. This is done by sequentially operating the deceleration from the smallest.

When the plurality of types of auxiliary brakes 22a to 22n include the engine brake, exhaust brake, compression pressure release engine brake, fluid type retarder, and electromagnetic type retarder described above, the deceleration (braking force) obtained from each of these auxiliary brakes. ) Increases in the order of the engine brake, the exhaust brake, the compression pressure release engine brake, the fluid type retarder, and the electromagnetic type retarder. Accordingly, the determination thresholds h0, h1, to h5 for sequentially operating the auxiliary brakes 22a to 22n are set to the auxiliary brakes 22a to 22n (engine brake, exhaust brake, compression pressure release engine brake, fluid retarder, electromagnetic H0 <h1 <h2 <h3 <h4 <h5
Set as. The determination threshold value h5 is set as the total deceleration (total braking force) when all the auxiliary brakes 22a to 22n are operated.

  Then, it is determined whether or not the target deceleration f0 obtained as described above exceeds the first determination threshold value h0 [step S2], and if it exceeds the determination threshold value h0, the engine brake having the smallest deceleration is operated [ Step S3]. When the target deceleration f0 is less than the first determination threshold value h0, the control returns to the braking control at the next timing without performing the deceleration control by operating the engine brake.

  When the engine brake is operated as described above, it is next determined whether or not the target deceleration f0 further exceeds the second determination threshold value h1 [step S4] and exceeds the determination threshold value h1. Further, the exhaust brake is operated [step S5]. That is, when the target deceleration f0 exceeds the second determination threshold value h1, the exhaust brake is operated in addition to the engine brake that has already been operated. When the target deceleration f0 is less than the second determination threshold value h1, only the operation of the engine brake described above is permitted, and the next timing is not performed without further operation of the auxiliary brake including the exhaust brake. Return to braking control at.

  When the exhaust brake is operated, it is next determined whether or not the target deceleration f0 further exceeds the third determination threshold value h2 [step S6]. When the release engine brake is activated [step S7] and the compression pressure release engine brake is activated, it is further determined whether or not the target deceleration f0 exceeds the fourth determination threshold value h3 [step S8]. When the target deceleration f0 exceeds the fourth determination threshold value h3, the retarder is driven weakly [step S9]. When the retarder is driven weakly, the target deceleration f0 further sets the fifth determination threshold value h4. It is determined whether or not it exceeds [Step S10]. When the target deceleration f0 exceeds the fifth determination threshold value h4, the retarder is driven strongly [step S11].

  When the target deceleration f0 is less than the above-described determination threshold values h2 to h4, the brake control is returned to the next timing without operating any further auxiliary brakes. Then, as described above, according to the target deceleration f0, the plurality of types of auxiliary brakes 22a to 22n are sequentially operated in descending order of the deceleration, thereby obtaining a desired deceleration. The inter-vehicle distance control is executed.

  However, there are cases where the target deceleration f0 cannot be achieved even when all of the plural types of auxiliary brakes 22a to 22n are operated. Therefore, when all of the plural types of auxiliary brakes 22a to 22n are operated, the total deceleration (determination threshold) h5 obtained when the target deceleration f0 and all of the auxiliary brakes 22a to 22n are operated next. [Step S12]. When the target deceleration f0 exceeds the total deceleration (determination threshold) h5, as described above, the difference between the target deceleration f0 and the total deceleration (determination threshold) h5 can be determined only by operating the auxiliary brakes 22a to 22n. It is determined that the amount of deceleration is insufficient, and the chamber pressure for the main brake 26 is calculated to generate this insufficient deceleration by the main brake 26 [step S13]. Then, the main brake 26 is driven using the chamber pressure, and a deceleration corresponding to the target deceleration f0 is generated using all the brakes including the auxiliary brakes 22a to 22n described above [step S14]. It should be noted that such deceleration control is similarly executed for the target deceleration f0 obtained when the above-described interruption is detected.

  Thus, according to the auto-cruise control device that executes the inter-vehicle distance control with respect to the preceding vehicle B by the deceleration control as described above, the deceleration according to the target deceleration f0 obtained according to the inter-vehicle distance and relative speed with the preceding vehicle B. Since the engine brake is sequentially operated from the engine brake with the smallest engine brake to the exhaust pressure brake, the compression pressure release engine brake, and the retarder, the deceleration required for the inter-vehicle distance control can be easily generated. In addition, if the deceleration is insufficient even when all of the plurality of types of auxiliary brakes 22a to 22n are operated, the insufficient deceleration is calculated and the chamber pressure corresponding to the insufficient deceleration is generated. Since the main brake 26 is operated, the deceleration required for the inter-vehicle distance control can be reliably generated, and the applicable range of the inter-vehicle distance control can be expanded. In other words, conventionally, the inter-vehicle distance can be properly maintained even under circumstances so that the inter-vehicle distance cannot be maintained unless the brake is operated by the driver, so that the driving comfort by the auto cruise control is kept good. Is possible.

  Further, when the main brake 26 is operated, unlike the case where the auxiliary brakes 22a to 22n are controlled to be turned on / off, the shortage deceleration is reduced from the main brake 26 according to the amount of deceleration that the auxiliary brakes 22a to 22n are insufficient. Since the required chamber pressure is obtained and the main brake 26 is operated under this chamber pressure, fine deceleration control can be performed. Therefore, it is appropriate even when the preceding vehicle B decelerates or when traveling on a downhill road, especially when the vehicle weight is increased due to the load on the truck or the like and acceleration more than expected is applied, and the vehicle speed gradually increases. Thus, it is possible to achieve a stable inter-vehicle distance control by applying an appropriate braking force.

  The present invention is not limited to the embodiment described above. The above-described operation control of the auxiliary brake may be executed according to the type of auxiliary brake installed in the vehicle. In short, a plurality of types of auxiliary brakes installed in the vehicle are reduced in deceleration. It is sufficient to operate in order from the one. In addition, for the detection of the inter-vehicle distance from the preceding vehicle A and the interrupt determination described above, instead of using the output of an inter-vehicle distance sensor such as a laser radar or a millimeter wave radar, for example, a vehicle front image captured by an in-vehicle camera is used. For example, various methods can be applied.

  Further, in the embodiment, the fuel injection amount is determined based on the pseudo accelerator opening information, and thus the vehicle speed control is performed by the engine ECU 12, but the vehicle speed, the inter-vehicle distance, the relative vehicle speed, etc. are calculated without obtaining the pseudo accelerator opening. Accordingly, the speed may be controlled by directly obtaining the fuel injection amount. In addition, the present invention can be variously modified and implemented without departing from the scope of the invention.

The figure which shows the concept of the inter-vehicle distance control in auto-cruise control. The schematic block diagram of an electronic main brake. The principal part schematic block diagram of the auto-cruise control apparatus which concerns on one Embodiment of this invention. The figure which shows an example of the control procedure of the deceleration control used with the automatic cruise control apparatus shown in FIG.

Explanation of symbols

12 Engine ECU
DESCRIPTION OF SYMBOLS 13 Accelerator opening degree increase / decrease control part 17 Vehicle speed increase / decrease control part 18 Target deceleration control part 20 Target braking force calculation part 21 Auxiliary brake control part 22a-22n Auxiliary brake 23 Auxiliary brake braking force calculation part 25 Target chamber pressure calculation part 26 Main brake 27 Interrupt judgment part

Claims (4)

An auto-cruise control device that is provided in a vehicle having a main brake and a plurality of types of auxiliary brakes and that performs inter-vehicle distance control that maintains a constant inter-vehicle distance from a preceding vehicle,
Target deceleration calculation means for calculating a target deceleration for the host vehicle from the inter-vehicle distance with the preceding vehicle and the relative speed with the preceding vehicle;
Auxiliary brake control means for sequentially operating the plurality of types of auxiliary brakes according to the calculated target deceleration, in order from an auxiliary brake with a small deceleration;
Main brake control means for operating the main brake according to a deceleration difference between the total deceleration and the target deceleration when the total deceleration due to the operation of all of the plurality of types of auxiliary brakes is less than the target deceleration An auto cruise control device comprising:   2. The auto cruise control according to claim 1, wherein the main brake control means obtains a chamber pressure that determines a braking force of the main brake according to a deceleration difference between the total deceleration and the target deceleration. apparatus. The auto cruise control device according to claim 1,
An interrupt determination means for determining whether or not there is a sudden change in the inter-vehicle distance with the preceding vehicle, and detecting as an interrupt of another vehicle ahead of the host vehicle when the inter-vehicle distance decreases rapidly;
An auto-cruise control device further comprising target deceleration correction means for gradually increasing the target deceleration when detecting this interruption.   The target deceleration correction means corrects the target deceleration at every predetermined cycle, and increases the previous target deceleration by a certain ratio to a preset deceleration limit value to increase the current target The automatic cruise control device according to claim 3, wherein the deceleration is obtained.

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