JP2781032B2 - Constant speed traveling control device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Overview] The present invention relates to a constant speed traveling control device having a resume function, and when a vehicle speed when a resume switch is operated is lower than a predetermined speed, a target vehicle speed for control is set to the predetermined speed. Thus, the vehicle speed is smoothly increased from a low speed state (particularly, a vehicle stopped state).

[Industrial applications]

The present invention relates to a constant speed traveling control device having a resume function.

[Conventional technology]

2. Description of the Related Art In recent years, constant speed traveling control for controlling a vehicle speed to automatically become a stored vehicle speed has become widespread. Such a constant speed traveling control device generally stores a vehicle speed obtained from a vehicle speed sensor in response to operation of a set switch as a stored vehicle speed, and thereafter controls the engine so that the vehicle speed matches the stored vehicle speed. However, there is a response delay or play in the actuator that opens and closes the throttle valve, causing the opening and closing of the slot valve to be delayed.Especially, when the vehicle speed is low, the engine speed is low and the torque is small. Change does not follow.

Therefore, a low speed limit value is set in advance (for example,
40km / h), when the vehicle speed falls below the low speed limit value during constant speed traveling control, the constant speed traveling control is interrupted.

Further, as a control related to the constant-speed traveling control, there is a resume control for temporarily stopping the constant-speed traveling control and then controlling the engine again so that the vehicle speed becomes the set vehicle speed in the previous constant-speed traveling control. For example, if the vehicle stops once after the constant speed driving control is released due to traffic congestion, etc., and when the traffic congestion is resolved and the vehicle starts running again, the resume switch is operated when the vehicle speed reaches the speed equal to or higher than the constant speed limit value. Is performed, the resume control is started. Then, the vehicle speed is increased so as to be the stored vehicle speed before the release of the constant speed traveling control, and when the vehicle speed reaches the stored vehicle speed, the increase in the vehicle speed is stopped and the control is shifted to the constant speed traveling control.

When increasing the vehicle speed as in the resume control, a value obtained by adding a predetermined value (for example, 3 km / h) to the current vehicle speed is set as a target vehicle speed for control, instead of comparing the stored vehicle speed and the vehicle speed, and thereafter, The target vehicle speed is increased at a predetermined increase rate (for example, 3 km / h per second) to accelerate quickly, and the throttle valve is opened and closed according to the difference between the vehicle speed and the target vehicle speed so that the vehicle speed follows the target vehicle speed. I try to control.

In such a case, the vehicle speed is equal to or higher than the constant low speed limit value, the engine speed is high, and the torque is sufficient.
The actual vehicle speed also increases at a predetermined increase rate following the target vehicle speed.

[Problems to be solved by the invention]

In the conventional constant-speed traveling control device, when the resume switch is operated in a state of being equal to or less than the low speed limit value, the resume control is not executed, and to start the resume control,
It was necessary to operate the resume switch after the vehicle speed became equal to or higher than the low speed limit value, and the operation was troublesome.

Therefore, it is demanded that the above-described resume control can be started even in a state where the resume control is equal to or lower than the low speed limit value (particularly, in a vehicle stopped state). However, in this case, at a vehicle speed lower than the low speed limit value, even if the actuator is operated with an increase in the target vehicle speed, the vehicle speed does not easily follow the increase in the target vehicle speed due to play, response delay, and further small torque. However, there is a problem that the vehicle speed cannot be increased quickly.

An object of the present invention is to solve such a problem, and an object of the present invention is to provide a constant-speed cruise control device that can quickly increase the vehicle speed even when the resume control is started in a state of being equal to or lower than a low speed limit value. And

[Means for solving the problem]

In order to solve the above-mentioned problems, the present invention provides a vehicle speed storage unit for storing a vehicle speed at which constant speed traveling is to be performed, a vehicle speed detecting unit for detecting the vehicle speed, and a constant speed traveling again using the stored vehicle speed in the previous constant speed traveling control. A resume switch for performing control; a target vehicle speed holding unit that stores an output of the vehicle speed detection unit as a target vehicle speed in response to operation of the resume switch; and a target vehicle speed holding unit in response to operation of the resume switch. A target vehicle speed changing unit that increases the target vehicle speed stored in the vehicle until the vehicle speed reaches the stored vehicle speed stored in the storage vehicle speed holding unit. The engine is controlled so that the target vehicle speed and the output of the vehicle speed calculation unit become equal. A target vehicle speed limiter that changes the target vehicle speed to the predetermined speed when the target vehicle speed is equal to or lower than a predetermined speed. The is characterized in that it comprises.

(Operation)

When the resume switch is operated, the target vehicle speed holding unit stores the vehicle speed detected by the vehicle speed detection unit as the target vehicle speed. The target vehicle speed limiter unit changes the target vehicle speed to the predetermined speed if the target vehicle speed stored in the target vehicle speed holding unit is equal to or lower than the predetermined speed. If so, the target vehicle speed is not changed.

On the other hand, in response to the operation of the resume switch, the target vehicle speed changing unit increases the target vehicle speed stored in the target vehicle speed holding unit until the target vehicle speed reaches the vehicle speed stored in the stored vehicle speed holding unit. The control unit controls the engine such that the vehicle speed detected by the vehicle speed detection unit becomes the target vehicle speed.

(Example of the invention)

Hereinafter, embodiments of the present invention will be described with reference to the drawings. First
FIG. 1 is a block diagram showing an embodiment of the present invention.

The control circuit 1 drives the actuator 2 in response to the vehicle speed sensor 4, the set / coast switch 5, the resume / accelerator switch 6, and the cancel signal to control the opening / closing of the throttle valve 3, thereby performing the constant speed traveling control. is there. The control circuit 1 is constituted by a microcomputer or the like.

The actuator 2 is controlled by a control signal Cont from the control circuit 1, and adjusts the opening of the throttle valve 3.

The throttle valve 3 controls the amount of air taken into the engine (not shown). When the throttle valve 3 is opened, the engine speed increases and the vehicle speed increases. When the throttle valve 3 is closed, the engine speed increases. Power decreases and vehicle speed decreases.

The vehicle speed sensor 4 supplies a pulse signal synchronized with the rotation of the wheels to the control circuit 1. The control circuit 1 is configured to obtain the vehicle speed from the cycle of the pulse signal.

The set / coast switch 5 is an operation switch for starting the constant speed traveling control and for reducing the stored vehicle speed in the coast control. When the set / coast switch 5 is operated in a state where the constant-speed traveling control is not performed, the control circuit 1 performs the set control of the constant-speed traveling control, and performs the set / coast in a state where the constant-speed traveling control is performed. When the coast switch 5 is operated, the control circuit 1 performs coast control.

The resume / accelerator switch 6 is an operation switch for restarting the constant speed traveling control and increasing the stored vehicle speed in the accelerator control. When the resume / accelerator switch 6 is operated in a state where the constant speed traveling control is not performed, the control circuit 1 restarts the constant speed traveling control, that is, performs the resume control, and the constant speed traveling control is performed. When the resume / accelerator switch 6 is operated in this state, the control circuit 1 performs accelerator control.

On the other hand, the cancel signal generator 7 detects a brake operation, a clutch operation, and the like, and outputs a cancel signal for instructing the control circuit 1 to cancel the constant speed traveling control.
When the pulse signal output from the vehicle speed sensor 4 becomes equal to or lower than the lower limit (constant speed limit) of the control separately from the generation of the cancel signal from the cancel signal generator 7, the control circuit 1 sets the constant except for the resume control. It is configured to cancel the high speed traveling control.

The driving force of the engine is transmitted to the wheels via an automatic transmission (not shown). The automatic transmission automatically increases the gear ratio as the vehicle speed increases, thereby efficiently increasing the driving force of the engine. To be communicated to.

Next, the operation of this embodiment will be described. FIG. 2 is a flowchart showing the operation of the control circuit 1. Incidentally, although not shown, when the power is turned on, the control circuit 1 shifts to a cancel mode, which will be described later, as an initial process.
0 km / h is set to Vm and the target vehicle speed VD under control.

First, the process proceeds from step S1 to step S2 every time 50 ms has elapsed, calculates the vehicle speed based on the pulse signal from the vehicle speed sensor 4, and performs a filter process of the vehicle speed in step S3 to obtain the current vehicle speed Vn. This filter processing is, for example, to multiply the result of the filter processing performed last time by 3/4, add the vehicle speed calculated in step S2 by 1/4, and then add step S4.

In step S4, the control advance vehicle speed Vsk is calculated. The control advance vehicle speed Vsk is used to advance and compensate for an operation delay of the actuator and a delay time due to hysteresis or play of the throttle and the drive system. The control advance vehicle speed Vsk is obtained by multiplying the difference between the vehicle speed Vn and the previous vehicle speed Vn-1 by a factor (K times) and adding the result to the vehicle speed Vn. This coefficient K is set according to the delay time of the control system.

Thereafter, the process proceeds to step S5, where the control mode is set and the stored vehicle speed is stored in accordance with the state of the set / coast switch 5, the resume / accelerator switch 6, the cancel signal generator 7, and the like, as will be described later. Move on. In step S6, a process of changing the target vehicle speed during accelerator control or coast control is performed, and the process proceeds to step S7. Actuator control is performed according to the target vehicle speed and the vehicle speed Vn, and the control mode, and the process proceeds to step S8.

Next, the flowchart of FIG. 2 will be described in detail. FIG. 3 is a detailed flowchart of step S5, and FIG.
The drawing is a detailed flowchart of step S6, and FIG. 5 is a detailed flowchart of step S7. In addition, each mode such as cancel, cancel set, set, accelerator, resume, and coast described later is mutually exclusive,
When another mode is set in any of the modes, the original mode is released.

 First, step S5 will be described in detail with reference to FIG.

The process proceeds from step R1 to R2, where it is determined whether the vehicle speed Vn is equal to or higher than the aforementioned low speed limit value C (for example, 30 kg / h), and if the vehicle speed Vn is equal to or lower than the low speed limit value C, step R3 is performed. Then, it is determined whether or not the current mode is the resume mode. If the current mode is the resume mode, the process proceeds to step R4. If the current mode is not the resume mode, the process proceeds to step R13, the cancel mode is set, and the process proceeds to step R27. On the other hand, if the vehicle speed Vn is higher than the low speed limit value C in Step R2, Step R4
Move to

In step R4, it is determined whether or not a cancel signal is generated. If the cancel signal is generated, the process proceeds to step R13 to cancel the control, the cancel mode is set, and if the cancel signal is not generated, the process proceeds to step R13. R5
Move to In step R5, it is determined whether or not the resume / accelerator switch 6 is on. If the resume / accelerator switch 6 is on, the process proceeds to step R14 in order to perform a process related to the operation of the resume / accelerator switch 6, and if not, the process proceeds to step R6. Move to In step R6, it is determined whether or not the set / coast switch 5 is operated, that is, whether or not the switch is on. If the switch is on, the process proceeds to step R21 in order to perform processing related to the operation of the set / coast switch 5. If not, that is, if the cancel signal has not been generated and the resume / accelerator switch 6 and the set / coast switch 5 have not been operated, step R7
Move to

In step R21, it is determined whether or not the current mode is the cancel mode or the cancel set mode (a mode indicating that the set / coast switch is once turned on in the cancel mode in order to start the constant speed traveling control). If so, that is, when the set / coast switch 5 is turned on during cancellation of the cruise control, the cancel set mode is set as a preparation stage of the set control (step R24), and the process proceeds to step R27. For example, in order to start the coast control when the set / coast switch 5 is turned on during the cruise control, the current vehicle speed Vn is stored in the storage vehicle speed Vm (step R22), and the coast mode is set (step R23). ), And proceed to step R27.

On the other hand, when it is determined in step R6 that the set / coast switch 5 is not in the on state, and the process proceeds to step R7, in step R7, the resume accepting flag indicating that the resume control has been started is reset, and the process proceeds to step R8. In step R8, it is determined whether or not the resume mode has been set. If the resume mode has been set, the process proceeds to step R9, and if not, the process proceeds to step R10. In step R9, the vehicle speed Vn is 3 km / h with respect to the stored vehicle speed Vm.
It is determined whether or not the range has been reached. If the range has been reached, the routine proceeds to step R12 to set the set mode in order to restart the constant speed running at the stored vehicle speed Vm. On the other hand, if not reached, the process proceeds to Step R10.

In step R10, it is determined whether the cancel set mode is set. This step R10 is set /
Since this is executed when the coast switch 5 is in the off state, if the cancel set mode is set, it is determined that the set / coast switch 5 shifts from the on state to the off state to start the constant speed traveling control. After moving to step R11, the current vehicle speed is set to the stored vehicle speed Vm, then the set mode is set (step R12), and the process moves to step R27.
On the other hand, if the cancel set mode has not been set, the process proceeds to step R25, and it is determined whether the coast or accelerator mode has been set. If so, both the set / coast switch 5 and the resume / accel switch 6 are released. Therefore, the vehicle speed wn is stored in the stored vehicle speed Vm in order to perform the constant speed running control at the current vehicle speed, which means the end of the coast control or the accelerator control.
Is stored (step R26), the set mode is set (step R12), and the routine goes to step R27. Step R2
If the coast or accelerator mode is not set in step 5, the process immediately proceeds to step R27.

Next, in step R5, the resume / accelerator switch 6
Is determined to be on and the process proceeds to step R14. In step R14, it is determined whether or not the resume reception flag is set. This flag means that the resume / accelerator switch 6 is being operated to perform the resume control. When the resume control is not being performed, this flag is reset. Therefore, when the resume / accelerator switch 6 is turned on for the first time, the process proceeds from step R14 to step R15. In step R15, it is determined whether or not the current mode is the cancel or cancel set mode. If the current mode is the cancel or cancel set mode, the resume / acceleration switch 6 is operated during the cancel to indicate that the resume / accelerator switch 6 has been operated. Then, the process proceeds to step R17 to perform processing relating to the accelerator control. Otherwise, the process proceeds to step R28 to perform processing related to the accelerator control. ), And proceed to step R27.

In step R17, it is determined whether or not the stored vehicle speed Vm immediately before entering the cancel or cancel set mode is 0 km / h, and if it is 0 km / h, the resume control is not established, so the process proceeds to step R18 to set the cancel mode. Then, the process proceeds to Step R27. On the other hand, in step R17, the stored vehicle speed
If Vm is not 0 km / h, the process proceeds to step R19 to perform resume control, sets the resume mode, and sets the resume accept flag (step R2).
0), proceed to step R8.

Subsequently, in step R14, when it is determined that the resume reception flag is set and the process proceeds to step R16, it is determined whether or not the current mode is the set mode, and when not, the process proceeds to step R19. Resume control, and if the mode is the set mode, the process proceeds to step R8. Therefore, even while the resume / accelerator switch 6 is being operated, the process moves from step R9 where the vehicle speed Vn ≧ the stored vehicle speed Vm−3 km / h to step R12, the mode is changed from the resume mode to the set mode, and the constant speed traveling control is resumed. You.

Here, the operation of step S5 will be described by taking the operation of each switch and the generation state of the cancel signal as an example. First, when the set / coast switch 5 is turned on for the first time after turning on the power of the cruise control device, the control goes to steps R4 and R5 to step R5.
Move from step 6 to step R21. After the power is turned on, the mode is the cancel mode, so that the process moves from step R21 to step R24 to set the cancel set mode. Thereafter, when the set / coast switch 5 is turned off, the process proceeds from step R6 to step R7, and after the resume acceptance flag is reset, the process proceeds to step R11 via steps R8 and R10. Then, the current vehicle speed Vn is stored in the stored vehicle speed Vm, and step R1
The set mode is set in 2 and the constant-speed running control is started.

If the resume / accelerator switch 6 is turned on in this state, the process proceeds to step R14. At this time, since the resume accept flag is in the reset state and the set mode, the process goes from step R14 to step R15 to step R2.
8, the current vehicle speed Vn is stored in the stored vehicle speed Vm, and after the accelerator mode is set (step R29), the process proceeds to step R27.
Then, the accelerator control is started. When the resume / accelerator switch 6 is turned off again, the process proceeds from step R5 to step R7 via step R6, resets the resume acceptance flag, and proceeds to step R25 via steps R8 and R10. Then, the current vehicle speed Vn is stored in the stored vehicle speed Vm, the set mode is set in step R12, and the constant speed traveling control is performed at the increased stored vehicle speed Vm.

In addition, the set / coast switch 5
Is turned on, the process moves from step R6 to step R21. At this time, since the set mode is set, the process moves from step R21 to step R22, the current vehicle speed Vn is stored in the stored vehicle speed Vm, and the coast mode is set (step R23).
Thereafter, the flow shifts to step R27, where coast control is started. Then, when the set / coast switch 5 is turned off again, the process proceeds from step R6 to step R7, the resume acceptance flag is reset, and the process proceeds to step R25 via steps R8 and R10. Then, the current vehicle speed Vn is stored in the stored vehicle speed Vm, the set mode is set in step R12, and the constant speed traveling control is performed at the reduced stored vehicle speed Vm.

Thereafter, when a cancel signal is generated from the cancel signal generator 7 due to the brake being depressed or the like, Step R4
From step R13 to set the cancel mode,
The cruise control is released. At this time, the stored vehicle speed Vm remains without being erased.

Then, when the cruise control is canceled,
When the accelerator switch 6 is operated, the process moves from step R5 to step R14. At this time, the resume accept flag is in the reset state and is in the cancel mode.
The process moves from step R14 to step R17 via step R15. At this time, since the stored vehicle speed Vm is stored, the process proceeds to step R19, where the resume is set, and the resume reception flag is set. Then, the process proceeds to step R9 via step R8, and if the vehicle speed Vn has not reached a value 3 km / h lower than the stored vehicle speed Vm, the process proceeds to step R27 via steps R10 and R25, and if it has reached step R12,
Then, the set mode is set and the cruise control is restarted.

If the resume / accelerator switch 6 is kept pressed during the resume control, the process proceeds from step R5 to step R16 via step R14 because the resume accept flag has already been set. If the set mode has already been set at that time, that is, if the process has shifted from the resume control to the constant speed traveling control, steps R8 and R1 are executed.
The process moves to step R27 via 0 and R25. Meanwhile, step R1
If it is not the set mode in step 6, the process goes to step R19 to reset the resume mode and reset the resume accept flag. Thus, even if a cancel signal is temporarily generated when the resume / accel switch 6 is in the on state and the cancel mode is set, if the resume / accel switch 6 is in the on state until the cancel signal disappears, the resume mode is resumed. Return to mode.

Next, the target vehicle speed control in step R6 will be described with reference to FIG. Moving from step Q1 to step Q2, it is determined whether the current mode is the accelerator mode or the resume mode, and if so, the target vehicle speed VD under control is determined.
Step Q3 to perform processing to gradually increase
Move to

In the process of increasing the target vehicle speed, first, a value A (for example, 3 km / h) is added to the current vehicle speed Vn and given as a target vehicle speed, thereby compensating for a delay in the control system. B (for example, 2 km / h).

Therefore, in step Q3, it is determined whether or not a step flag indicating that the target vehicle speed increasing process has already been started is set, that is, a value obtained by adding the value A to the vehicle speed Vn is substituted as the target vehicle speed VD. Determine if Immediately after the resume / accelerator switch 6 is operated, the step flag is not set because the step flag is not set (step Q4), and the value obtained by adding the predetermined value A to the vehicle speed Vn is substituted for the target vehicle speed VD (step Q5). ), And proceed to step Q11. In step Q11, the target vehicle speed VD is set to the low speed limit value C.
Judge whether it is smaller than
Then, the value C is substituted for the target vehicle speed VD, and the process proceeds to step Q11.

After that, the process moves from step Q3 to step Q6 until the step flag is reset, and the target vehicle speed VD is increased by the value B / 20, which is the rate of increase of the target vehicle speed in 50 ms, and
Move to step Q13 via Q11.

If the current mode is neither the accelerator mode nor the resume mode in step Q2, it is not necessary to increase the target vehicle speed. Therefore, the step flag is reset in step Q7, and if the current mode is the set mode (step Q8 ), Giving the stored vehicle speed Vm to the target vehicle speed VD (step Q1)
0) If it is not the set mode, it means one of the cancel mode, the cancel set mode, and the coast mode, so 0 is given to the target vehicle speed VD (step Q9), and then the process proceeds to step Q13.

Next, the actuator control in step S7 will be described in detail with reference to FIG.

The process moves from step P1 to P2 to determine whether the current mode is any of the cancel, cancel set, and coast modes. If so, the process moves to step P7, where the control duty Dn is set to 0 and the process moves to step P8. Move on. On the other hand, if not, the process proceeds to Step P3. In step P3, the control duty Dn is performed based on the target vehicle speed VD and the current advance vehicle speed Vsk.
Is calculated. This control duty Dn is obtained by the following equation.

Then, the process proceeds to Step P4 where the vehicle speed Vn is set to the low speed limit value C.
It is determined whether or not the above is true. If the value is equal to or more than the low speed limit value C, the process directly proceeds to step P8. If the value is less than the low speed limit value C, the process proceeds to step P5 to perform the limit process of the control duty Dn.

In step P5, it is determined whether or not the control duty Dn is equal to or more than the limit value D (for example, 70%).
Is substituted for D. Note that the control duty Dn is equal to the limit value D.
If it is less, the process proceeds to Step P8.

Then, in step P8, a control signal Cont corresponding to the control duty Dn is output to drive the actuator, open and close the throttle valve, and then proceed to step P9.

That is, when the resume / accelerator switch 6 is operated in a state where the vehicle speed is equal to or lower than the low speed limit value C, the target vehicle speed VD temporarily becomes the vehicle speed Vn + A. The limit value C is stored. That is, since a large value is set as the target vehicle speed VD, the vehicle speed deviation ΔV (= VD−Vsk) increases, and the control duty Dn also increases accordingly. Therefore, the throttle valve is widely opened by the actuator.
The acceleration of the vehicle also increases.

When the vehicle accelerates from a stopped state, the automatic transmission changes the speed until the low-speed limit value C is reached. However, if the throttle valve opening is too large, the shift before and after the shift-up is performed. The difference between the subsequent accelerations increases and the advance vehicle speed Vsk fluctuates greatly, that is, the target vehicle speed Vsk
The difference between D and the advance vehicle speed Vsk greatly fluctuates, and the control duty Dn fluctuates accordingly, causing hunting in the vehicle speed.

Therefore, in the present embodiment, when the vehicle speed Vn is equal to or lower than the low speed limit value, the control duty Dn is limited to a value D (for example, 70%) to reduce the acceleration before the upshift, thereby increasing and decreasing the speed before the upshift. The difference between the accelerations is reduced so that the variation in the advance vehicle speed Vsk is reduced.

As described above, in the present embodiment, when the target vehicle speed VD is equal to or less than the low speed limit value, the target vehicle speed VD is converted into the low speed limit value, and the constant speed traveling control is performed based on this. At the vehicle speed of, the vehicle speed deviation ΔV increases and the actuator operates greatly. Therefore, although there is a temporary response delay due to the delay of the actuator, the throttle valve is greatly opened thereafter and acceleration can be performed quickly.

Also, when the vehicle speed is higher than the low speed limit value, that is, when the engine speed is large and the torque is sufficient, the target vehicle speed VD is not changed to the low speed limit value, and the vehicle speed is increased to the stored vehicle speed with a quick and safe acceleration. Can be done.

〔The invention's effect〕

As described above in detail, according to the present invention, when the target vehicle speed is equal to or lower than the predetermined speed, the target vehicle speed is converted into the predetermined speed,
Based on this, constant-speed running control is performed, so at vehicle speeds below the low speed limit value, the vehicle speed deviation becomes larger than before, so the throttle valve opens greatly,
Acceleration can be performed quickly.

Further, when the vehicle speed is higher than the predetermined speed, that is, when the engine speed is large and the torque is sufficient, the target vehicle speed is not changed to the predetermined speed, and the vehicle speed can be increased to the stored vehicle speed with a quick and safe acceleration. .

[Brief description of the drawings]

FIG. 1 is a block diagram showing an embodiment of the present invention, FIG. 2 is a flowchart showing the operation of the control circuit 1, FIG. 3 is a detailed flowchart of step S5, FIG. FIG. 5 is a detailed flowchart of step S7. In the figure, 1: control circuit, 2: actuator, 3: throttle valve, 4: vehicle speed sensor, 5: set / coast switch, 6:
Resume / Accel switch, 7: Cancel signal generator

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁶ , DB name) B60K 31/00 F02D 29/02 F02D 41/14 320

Claims (1)

(57) [Claims] 1. A vehicle speed holding unit for storing a vehicle speed at which constant speed traveling is to be performed, a vehicle speed detecting unit for detecting a vehicle speed, and a resume for performing constant speed traveling control again with the stored vehicle speed in the previous constant speed traveling control. A switch, a target vehicle speed holding unit that stores an output of the vehicle speed detecting unit as a target vehicle speed in response to the operation of the resume switch, and a target stored in the target vehicle speed holding unit in response to the operation of the resume switch. A target vehicle speed changing unit that increases the vehicle speed until the vehicle speed reaches the stored vehicle speed stored in the storage vehicle speed holding unit; and a control unit that controls the engine so that the target vehicle speed and the output of the vehicle speed calculation unit become equal. A cruise control device having a target vehicle speed limiter unit that changes the target vehicle speed to the predetermined speed when the target vehicle speed is equal to or lower than a predetermined speed. That cruise control apparatus.