JP2554267B2 - Cruise control device - Google Patents

Description

TECHNICAL FIELD The present invention relates to a cruise control device for automatically causing a vehicle to run at a constant speed.

2. Description of the Related Art Conventionally, in this type of cruise control device, the target vehicle speed is set according to the vehicle speed when the auto cruise switch is set, and the target throttle valve opening of the engine corresponding to the target vehicle speed is initially set. Then, at a predetermined control cycle, the target vehicle speed and the actual vehicle speed actually detected at that time are compared, and the correction amount of the throttle valve opening is calculated according to the difference to correct the target throttle valve opening. Feedback control means is provided to drive the actuator so that the actually detected vehicle speed becomes the target vehicle speed, and to appropriately adjust the throttle valve opening.

Therefore, if the above-mentioned feedback control is always executed at a constant control cycle, for example, when traveling uphill or downhill, the difference between the actual vehicle speed and the target vehicle speed becomes large in the control interval, or Acceleration becomes large, and it takes time to converge the actual vehicle speed deviating from the target vehicle speed to the target vehicle speed, resulting in poor responsiveness.

The present invention has been made in consideration of the above points, and even if the difference between the actual vehicle speed and the target vehicle speed becomes large or the acceleration of the vehicle becomes large, feedback control is sufficiently performed in accordance with the change. The present invention provides a cruise control device that is capable of optimally responding to responsiveness.

In order to achieve the object, the present invention is detected in a cruise control device that adjusts the throttle valve opening so that the actual vehicle speed converges to the target vehicle speed according to the deviation between the target vehicle speed and the detected actual vehicle speed. Control of the slot valve opening for detecting the actual vehicle speed and converging it to the target vehicle speed according to the deviation between the actual vehicle speed and the target vehicle speed or the magnitude of the detected vehicle traveling acceleration with respect to a preset threshold value The control cycle for calculating the quantity is changed.

An embodiment of the present invention will be described in detail below with reference to the accompanying drawings.

FIG. 1 shows a basic configuration example of a cruise control device according to the present invention. A vehicle speed detector 1 for detecting the actual traveling speed of a vehicle, and an operation command and cancellation of cruise control according to on / off operations. The auto cruise main switch 2 for giving a command, the acceleration switch 3 for giving an acceleration command and a resume command for cruise control, the set switch 4 for giving a desired vehicle speed setting command and a deceleration command for cruise control, and an engine throttle valve opening degree are set. A throttle valve opening detector 5 for detecting, a control device 7 for executing cruise control by reading detection signals of the detectors 1 and 5 and command signals from the switches 2 to 4, and corresponding to the control signals. And an actuator 8 for opening and closing the throttle valve. To have.

As the control device 7, the input interface 71, CPU7
2, ROM 73 and RAM 74 for control, constant memory in which predetermined control characteristics required for cruise control are stored in advance
75, output interface 76.

An example of the contents of RAM74 is shown in FIG. 2, and a constant memory 7 is shown in FIG.
An example of the contents of 5 is shown.

As the actuator 8, the step motor can be rotated in the forward direction or the reverse direction by an appropriate amount through a driver in accordance with a control signal output from the control device 7 to drive the throttle valve in the opening direction or the closing direction. It has become.

Further, FIG. 4 shows a specific control configuration example in the control device 7.

In the cruise control device thus configured, when the auto cruise main switch 2 is turned off, the auto cruise flag in the RAM 74 of the control device 7 is reset and the cruise control is released. .

At this time, under the control of the CPU 72, the reference slot valve opening memory 751 in the constant memory 75 is selected, and the reference throttle valve opening preset in the memory is set as the target throttle valve opening as the target throttle valve opening in the RAM 74. It is registered in the opening memory 747. In the reference throttle valve opening memory 751, the throttle valve opening corresponding to the engine idle speed is set.

Further, the actual throttle valve opening detected by the throttle valve opening detector 5 is registered in the actual throttle valve opening memory 746 in the RAM 74.

Then, the value registered in the target throttle valve opening memory 747 is compared with the value registered in the actual throttle valve opening memory 746, and the throttle valve opening control unit 91 drives the actuator 8 appropriately according to the difference. A command is issued, whereby the actual throttle valve opening is held so as to be equal to the throttle valve opening corresponding to the idle speed of the engine.

At this time, it is possible to independently perform the opening / closing drive of the throttle valve by the accelerator pedal of the vehicle, irrespective of the control of holding the throttle valve at the idle position by the actuator 8 when the cruise control is released. It has become.

When the auto cruise main switch 2 is turned on, the auto cruise flag in the RAM 74 of the control device 7 is set and the auto cruise set state is entered.

Thereby, under the control of the CPU 72, the actual traveling speed of the vehicle detected by the vehicle speed detector 1 when the set switch 4 is turned on is registered in the actual vehicle speed memory 744 in the RAM 74, which is set as the target vehicle speed. Initialized in vehicle speed memory 745.

At the same time, the set throttle valve opening memory 752 in the constant memory 75 is selected. The target throttle valve opening characteristic with respect to the target vehicle speed is stored in the set throttle valve opening memory 752. As a characteristic of the target throttle valve opening with respect to the target vehicle speed, for example, as shown in FIG. 5, a target throttle valve opening characteristic corresponding to the target vehicle speed when the vehicle is traveling on a level ground is adopted.

Then, when setting the throttle valve opening memory 752
According to the target throttle valve opening characteristic for the target vehicle speed stored in, the target vehicle speed memory at that time 74
The target throttle valve opening corresponding to the target vehicle speed set to 5 is read out and initialized in the target throttle valve opening memory 747 and the initially set target throttle valve opening memory 748.

Then, the actuator 8 is driven by the throttle valve opening control unit 91 to rapidly move the throttle valve to the initially set target opening position.

Then, the actual vehicle speed and the actual throttle valve opening are respectively detected at the sampling cycle (for example, 0.5 seconds) set in the sampling timer 92, and the feedback control is performed in order to keep the actual traveling speed of the vehicle at the target vehicle speed. It is executed as follows.

That is, the difference between the actual vehicle speed detected by the vehicle speed detector 1 after the set switch 4 is operated and updated and registered in the actual vehicle speed memory 744 and the target vehicle speed registered in the target vehicle speed memory 745 is calculated as a vehicle speed deviation calculation. Requested in part 93. Then, the obtained difference is given to the throttle valve opening correction amount calculation unit 94, where it is multiplied by a constant constant read from a constant memory (not particularly shown) in the constant memory 75 to correct the throttle valve opening correction. The amount is calculated. Then, the calculated throttle valve opening correction amount is added to the target throttle valve opening previously registered in the target throttle valve opening memory 747 in the adding unit 95, and the corrected new target throttle valve opening is performed. The degree is updated and registered in the target throttle valve opening memory 747. At that time, the actual throttle valve opening detected by the throttle valve opening detector 5 is registered in the actual throttle valve opening memory 746. Therefore, the actual throttle valve opening and the target throttle valve opening memory are registered. The throttle valve opening control unit 91 compares the corrected target throttle valve opening with the corrected target throttle valve opening so that the actual throttle valve opening at that time becomes equal to the corrected target throttle valve. Through this, the actuator 8 is appropriately driven.

As described above, the target throttle valve opening is initially set according to the characteristics established in advance according to the target vehicle speed set when the set switch 4 is operated, and the target vehicle speed of the actual vehicle speed starts from the throttle valve opening. The target throttle valve opening is corrected on the basis of the deviation with respect to, and feedback control is performed so that the actual throttle valve opening becomes equal to the corrected throttle valve opening. The deviation between the target vehicle speed and the actual vehicle speed is reduced (and averaged), the vehicle speed is prevented from dropping and hunting is prevented, and the target vehicle speed is quickly and smoothly converged.

When the auto cruise main switch 2 is turned off, the cruise control in the control device 7 is immediately released.

Next, a case where the target vehicle speed is adjusted during the auto cruise will be described below.

When the driver operates the acceleration switch 3 during the auto cruise, an acceleration signal is generated during the operation period. In response to the generation of the acceleration signal, the CPU 72 selects the acceleration initial increment memory 754 in the constant memory 75.

The initial acceleration memory 754 stores the characteristic of incremental addition according to the actual vehicle speed at that time. The increment correction value read from the acceleration initial increment memory 754 is added to the value stored in the target throttle valve opening memory 747.

Therefore, the stored value of the target throttle valve opening memory 747 becomes large by the increment correction value, the step motor in the actuator 8 rotates by an angle corresponding to this, and the throttle valve opening also becomes large. Is realized.

On the other hand, the generation of the acceleration signal drives the acceleration signal duration timer 96, and the elapsed time of operating the acceleration switch 3 is counted. At the same time when the acceleration signal is generated, the acceleration pattern memory 755 in the constant memory 75 is selected.

The acceleration pattern memory 755 stores the characteristic of the incremental correction value required for acceleration according to the elapsed time. The incremental correction value read from this acceleration pattern memory 755 is
Further, it is added to the value stored in the target throttle valve opening memory 747.

As a result, the target value of the throttle valve opening becomes larger than the actual opening, so the CPU 72 drives the actuator 8 as described above, and increases the throttle valve opening with the increase of the elapsed time. I will let you.

When the desired acceleration ends and the operation of the acceleration switch 3 is stopped and the acceleration signal disappears, the CPU 72 causes the target vehicle speed memory 745
Then, the actual vehicle speed at that time is stored as the target vehicle speed.

At the same time, the post-acceleration decrement memory 756 in the constant memory 75 is selected. The post-acceleration decrement memory 765 stores the characteristic of the closing direction correction amount of the throttle valve opening that should be executed immediately after the acceleration signal disappears according to the actual vehicle speed.

Therefore, when the acceleration is completed,
The closing direction correction amount read from the 756 is added to the stored value of the target throttle valve opening memory 747, and the actuator 8 is adjusted so that the corrected target throttle opening is obtained.
Is driven.

In this way, the throttle valve opening is once reduced by a fixed amount determined by the actual vehicle speed at that time after the acceleration signal disappears. This prevents overshoot of the actual vehicle speed after the acceleration operation.

After that, cruise control for the new accelerated target vehicle speed is executed in the same manner as described above.

Further, when the driving vehicle operates the deceleration switch 4 during the auto cruise, the deceleration signal is generated during the operation period.

In response to the generation of this deceleration signal, the CPU 72 causes the constant memory 7
The deceleration reference opening memory 758 in 5 (or, instead, the reference throttle valve opening memory 751) is selected. The deceleration reference opening degree memory 758 stores a value close to the throttle valve opening degree during idle operation of the engine. As a result, a value close to the throttle valve opening during idle operation is registered in the target throttle valve opening memory 747.

As a result, the stored value of the target throttle valve opening memory 747 becomes smaller than the stored value of the actual throttle valve opening memory 746, the throttle valve is driven in the closing direction, and the initial deceleration of the vehicle is realized. .

In this case, the throttle valve opening value stored in the deceleration reference opening memory 758 may be a fixed value or may change according to the actual vehicle speed at that time.

When the desired deceleration ends and the operation of the set switch 4 is stopped, the deceleration signal disappears, and the CPU 72 accordingly selects the post-deceleration opening memory 757 in the constant memory 75.

At the same time, the target vehicle speed memory 745 stores the actual vehicle speed at that time as the target vehicle speed.

The post-deceleration opening memory 757 stores the characteristics of the throttle valve opening that should be set immediately after the deceleration signal corresponding to the actual vehicle speed disappears.

The value read from the post-deceleration opening memory 757 is stored in the target throttle valve opening memory 747 as the target throttle valve opening at that time.

Note that the throttle valve opening value in this case is the same as the throttle valve opening memory at setting for the same vehicle speed.
The value is preferably set to be smaller than the value stored in 752 and larger than the value stored in the reference throttle valve opening memory 751.

Thus, the throttle valve opening is set to a predetermined value determined by the actual vehicle speed at that time after the deceleration signal disappears. After that, cruise control for the new decelerated target vehicle speed is executed in the same manner as described above.

In the cruise control device as described above, particularly in the present invention, under the control of the control device 7, when the difference between the actual vehicle speed and the target vehicle speed exceeds the preset threshold value of the vehicle speed deviation, or the acceleration is increased. When the vehicle acceleration detected by a detector or obtained by differentiating the actual vehicle speed exceeds a preset threshold value, it is detected and the control cycle of feedback control is made shorter than usual. Therefore, the control cycle set in two stages is switched from the normal slow side to the fast side.

Therefore, by adopting such a control cycle switching means, the vehicle travels uphill or downhill in the auto-cruise state, and the difference (absolute value) between the actual vehicle speed and the target vehicle speed becomes a predetermined value or more, Alternatively, when the magnitude of the acceleration (deceleration) exceeds a predetermined level, the control cycle can be accelerated and the throttle valve opening can be adjusted frequently before the change becomes too large. Even if there is, the feedback control can follow the speed deviation or the acceleration change and can be performed with good responsiveness, and the actual vehicle speed can be quickly converged to the target vehicle speed.

The control cycle is set in advance in a number of stages of two or more, and the threshold value of the vehicle speed deviation between the actual vehicle speed and the target vehicle speed or the threshold value of the acceleration is set in multiple steps accordingly. Further, if the control cycle is switched in multiple stages according to the degree of the vehicle speed deviation or the magnitude of acceleration, more accurate feedback control can be performed.

Such control cycle switching means is composed of the actuator 8
As the above, it is particularly effective when using the one in which the diaphragm is operated by the negative pressure of the engine described above to adjust the opening of the throttle valve, but other than that, for example, the opening of the throttle valve is adjusted by a step motor. It is effective even when using the one that is made to be performed.

FIG. 6 shows an example of a flowchart of the auto-cruise process in the case where the control cycle switching means in the feedback control described above is applied.

In the control flow, first, in the first step, it is determined whether or not the initial value setting (θcruo setting) of the throttle valve opening has been completed.

At this time, if the auto-cruise flag is set, the difference V _D between the actual vehicle speed V _X and the target vehicle speed V _S is obtained assuming that the target value for feedback control has been initialized.

In the next second step, the absolute value of the vehicle speed deviation | V _D |
And a first threshold value V _L1 set in advance are compared.

At that time, if | V _D | <V _L1 , in the next third step, the absolute value of the acceleration dV _X obtained by differentiating the actual vehicle speed and the preset threshold value dV _L Are compared, |
It is determined whether dV _X | <dV _L.

Then, when it is determined that | V _D | ≧ V _L1 in the second step and | dV _X | ≧ dV _L is determined in the third step, the Assuming that the cruise state is somewhat disturbed, the control cycle in feedback control is switched to the fast side Tfast.

In the next fourth step, the absolute value of the vehicle speed deviation | V _D |
And a second threshold value V _L2 set in advance are compared. Here, the first threshold value V _L1 and the second threshold value V _L1
Relationship between _L2 are set such that V _L2> V _L1.

At that time, if | V _D |> V _L2, it is assumed that the vehicle is traveling on a slope and the vehicle speed deviation is large, and whether the vehicle is going uphill or downhill in the next fifth step. Is determined.

Here, in the case of a downhill, since the target throttle valve opening θcru at that time should be stuck at 0, it is determined whether or not θcru = 0.

At that time, if θcru = 0, it is determined that the vehicle is downhill, the deceleration flag Fvdwn is set (Fvdwn = 1), the auto cruise flag Fcru is reset (Fcru = 0), and the auto cruise process is temporarily canceled. After the vehicle is decelerated by the operation, the process jumps to the resume process that restores the auto cruise process temporarily canceled by the switch operation. Then, after the transition from the resume processing to the coast processing for coasting the vehicle, the automatic cruise processing is restored.

Further, if θcru ≠ 0, it is determined that the vehicle is an uphill road, the flag Fsu indicating the uphill road is set (Fsu = 1), and then
The routine proceeds to the routine for determining the throttle valve opening correction value θcorr.

When the throttle valve opening correction value θcorr is determined,
The correction value θcorr is added to the actual throttle valve opening θsm at that time to obtain the target throttle valve opening θcru (θcru = θcorr + θsm).

After that, flags related to acceleration processing and coast processing respectively
After Facc, Fcst and timers Tacc, Tcst are both reset (Facc = 0, Fcst = 0, Tacc = 0, Tcst = 0), the control cycle Tfast on the first side is set according to the target throttle valve opening θcru. Feedback control is executed.

In the third step, when it is determined that | dV _X | <dV _L, it is considered that the vehicle speed and the acceleration are stable, and the control cycle in the feedback control is switched to the slow side Tslow.

Then, in the next sixth step, a flag indicating an uphill
After confirming that Fsu is in the reset state,
r Move to decision routine, and target throttle valve opening θcru
After being calculated, the target throttle valve opening θcr
According to u, the feedback control is executed with the control cycle Tslow on the slow side.

In the fourth step, when | V _D | ≦ V _L2 is determined, it is considered that the vehicle speed deviation is not so large, and the process proceeds to the sixth step in which the flag Fsu indicating the uphill is set. Fsu = 0 depending on whether or not
If so, it is determined that the vehicle is a gentle downhill, and the target throttle valve opening θcru is obtained by moving to the θcorr determination routine, and according to the target throttle valve opening θcru,
Feedback control is executed with the control cycle Tfast on the first side.

At that time, if Fsu = 1, it is considered that the actual vehicle speed has caught up with the target vehicle speed near the top of the uphill,
In the next seventh step, absolute value of vehicle speed deviation | V _D |
And a preset third threshold value V _L3 are compared. Here, the first threshold value V _L1 and the third threshold value V _L1
Relationship between _L3 are set such that V _L1> V _L3.

At that time, if | V _D | <V _L3, it is determined that the vehicle speed deviation has become extremely small, and the auto cruise flag Fcru is reset (Fcru = 0), and the auto cruise according to the control cycle Tfast on the first side until then is set. Cancel processing.

If | V _D | ≧ V _L3, it is determined in the next eighth step whether or not the polarity of the vehicle speed deviation V _D has been inverted between + and −.

At that time, if the polarity is reversed, it is considered that the actual vehicle speed has reached the target vehicle speed, the auto cruise flag Fcru is reset (Fcru = 0), and the auto cruise according to the control cycle Tfast on the first side until then Cancel processing.

If the polarity is not reversed, it is considered that the cruise state is still somewhat disturbed and the routine proceeds to the θcorr determination routine to obtain the target throttle valve opening θcru,
Feedback control is executed with the control cycle Tfast on the first side according to the obtained target throttle valve opening θcru.

In the determination of the first step, when the auto cruise flag Fcru is in the reset state (Fcru = 0), it is determined that the auto cruise process is performed for the first time, and the routine proceeds to the routine for setting the target throttle valve opening initial value θcruo. The initial value θcruo of the target throttle valve opening is set.

Then, with Fcru = 1 and Fsu = 0, the normal control cycle Tsl
Enter the feedback control state by ow.

 The above processing will be repeated.

As described above, in the cruise control device according to the present invention, the target throttle valve opening is actually detected while being corrected in accordance with the difference between the target vehicle speed and the actually detected vehicle speed in the predetermined control cycle. When performing feedback control such that the vehicle speed becomes the target vehicle speed, the control cycle is set in advance in multiple stages, and the threshold value of the deviation between the vehicle speed actually detected and the target vehicle speed A threshold value for the detected acceleration of vehicle running is set in advance, and the control cycle can be switched back step by step according to the degree of deviation or the degree of acceleration discriminated by the threshold value. Then, as the difference between the actual vehicle speed and the target vehicle speed or the vehicle acceleration increases, the control cycle of the feedback control is shortened so that the difference between the actual vehicle speed and the target vehicle speed or the vehicle acceleration does not become too large. By appropriately calculating the control amount according to the actual vehicle speed at that time and frequently adjusting the throttle valve opening, the correction range per unit time of the feedback control is widened, and the difference between the actual vehicle speed and the target vehicle speed is increased. The increase in the vehicle speed or the acceleration of the vehicle is suppressed, and the increase in the control amount is suppressed, while sufficiently following the changes in the actual vehicle speed, the response speed and convergence to the target vehicle speed are performed quickly. It has an excellent advantage that it can be made.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of a cruise control device according to the present invention, and FIG. 2 is a block diagram of the same embodiment.
FIG. 3 is a diagram showing a table in RAM, FIG. 3 is a diagram showing a table of a constant memory in the same embodiment, and FIG. 4 is a block diagram showing a concrete control configuration example in the control device of the embodiment, and FIG. Is a diagram showing a characteristic of a target throttle valve opening with respect to a target vehicle speed, and FIG. 6 is a diagram showing an example of a control flow in an auto cruise process. 1 ... Vehicle speed detector, 2 ... Auto cruise main switch, 3 ... Acceleration switch, 4 ... Set switch, 5 ...
... Throttle valve opening detector, 7 ... Control device, 8 ...
… Actuator

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Ichiro Sakai 1-4-1 Chuo, Wako-shi, Saitama, Ltd. Inside the Honda R & D Co., Ltd. (72) Inventor Ken-ichiro Kinoshita 1-4-1 Chuo, Wako, Saitama Inside Honda R & D Co., Ltd. (56) Reference JP-A-61-244631 (JP, A)

Claims (2)

(57) [Claims] 1. A cruise control device for adjusting a throttle valve opening so as to converge an actual vehicle speed to a target vehicle speed in accordance with a deviation between the target vehicle speed and the detected actual vehicle speed. The control cycle for detecting the actual vehicle speed and calculating the control amount of the throttle valve opening for converging it to the target vehicle speed is changed according to the magnitude of the deviation between Cruise control device characterized by the above. 2. A cruise control device that adjusts the throttle valve opening so that the actual vehicle speed converges to the target vehicle speed in accordance with the deviation between the target vehicle speed and the detected actual vehicle speed. The control cycle for detecting the actual vehicle speed and calculating the control amount of the throttle valve opening so that the actual vehicle speed is converged to the target vehicle speed is changed according to the magnitude with respect to the preset threshold value. Characteristic cruise control device.