JPH08142714A - Automatic travel vehicle - Google Patents

Abstract

PURPOSE: To prevent the waste of fuel and the abrasion of a brake shoe caused by the concurrent continuation of acceleration and brake by gradually decreasing the braking force by a prescribed quantity when acceleration and brake are concurrently implemented and the balanced state that the vehicle speed detected value and the target vehicle speed coincide is detected. CONSTITUTION: A brake state switching judgment section 95 judges whether the brake state is proper or not based on the balance state between the set value of the target vehicle speed and the vehicle speed detected value under concurrent acceleration and brake and the detected result of the throttle opening, and it outputs the judged result to a braking force calculation section 94. When the judged result is a proper braking state, the brake force calculation section 94 outputs the calculated necessary braking force to a current instruction value calculation section 96 as it is. When the judged result is an unproper state, i.e., in the balanced state of acceleration and brake, the brake force calculation section 94 decreases the braking force by a prescribed quantity and outputs the braking force to the current instruction value calculation section 96. A vehicle can emerge from the unnecessary continued balanced state of concurrent acceleration and brake.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an automatic vehicle for controlling speed during traveling by controlling throttle opening and braking force.

[0002]

2. Description of the Related Art Conventionally, various types of automated vehicles used as golf carts for carrying luggage such as golf bags and people in golf courses have been developed. As this type of automatic vehicle, for example, the one disclosed in Japanese Patent Laid-Open No. 5-73144 is known. In the automatic vehicle disclosed in this publication, speed control during traveling is performed by controlling the throttle opening and controlling the braking force of regenerative braking by the starter dynamo.

[0003]

By the way, in the automatic vehicle disclosed in the above publication, the throttle opening and the braking force for regenerative braking are controlled independently of each other. In some cases, the vehicle speed may be equal to the target vehicle speed due to the balance between acceleration and braking with the vehicle open to some extent. In such a case, since the acceleration and the braking are continuously performed at the same time, the fuel is wastefully consumed and the brake shoes are unnecessarily worn.

The present invention has been made under such a background, and provides an automatic vehicle capable of preventing waste of fuel and abrasion of brake shoes due to simultaneous continuous acceleration and braking. The purpose is to do.

[0005]

According to a first aspect of the present invention, there is provided acceleration in an automatic traveling vehicle for controlling a vehicle speed by controlling a throttle opening and a braking force so that a detected vehicle speed value matches a target vehicle speed. A detection unit that detects a balance state in which the detected vehicle speed is substantially equal to the target vehicle speed by simultaneously performing braking, and a braking force that gradually decreases the braking force by a predetermined amount when the balance state is detected by the detection unit. And reducing means.

According to a second aspect of the present invention, in the first aspect of the invention, the detection means is in a state where the vehicle speed detection value is substantially equal to the target vehicle speed, and the throttle opening degree is a predetermined opening degree. It is characterized in that the balance state is detected by determining whether or not it is larger than the above.

[0007]

According to the present invention, the detecting means detects a balance state in which the vehicle speed detection value substantially coincides with the target vehicle speed by simultaneously performing acceleration and braking, and the braking force reducing means detects the balance state by the detecting means. When detected, the braking force is gradually reduced by a predetermined amount. Along with this, the throttle opening is also gradually reduced so that the vehicle speed matches the target vehicle speed. As a result, it is possible to get out of the equilibrium state in which acceleration and braking are continuously performed unnecessarily at the same time even though the vehicle speed matches the target vehicle speed.

Further, the detecting means detects the above-mentioned balanced state by determining whether or not the vehicle speed detection value is substantially equal to the target vehicle speed and the throttle opening is larger than a predetermined opening. It is possible to

[0009]

Embodiments of the present invention will be described below with reference to the drawings. (1) Configuration of Embodiments Configuration of Automated Driving Vehicle FIG. 1 is a block diagram showing the configuration of an automated traveling vehicle according to an embodiment of the present invention. The automatic vehicle shown in this figure is used as, for example, a golf cart used in a golf course, and is equipped with an engine 1 as in a normal automobile, and the engine 1 is provided with a V-belt type automatic transmission 1a. A transmission 3 for transmitting the supplied driving force to the rear wheels 2a, 2b which are driving wheels, a steering wheel 4 for steering the front wheels 2c, 2d, and an accelerator pedal 5 for adjusting the throttle opening to change the vehicle speed. And governor 6,
It has a brake pedal 7 for braking the vehicle and a mechanical brake mechanism such as drum brakes 8a to 8d.

Further, the automatic traveling vehicle is capable of automatic traveling in addition to ordinary manual traveling (hereinafter referred to as manual traveling). A controller 9 for controlling this automatic traveling, a steering driver 10, A steering motor 11, a throttle motor 12, a brake motor driver 13, a brake motor 14, an electromagnetic brake 15, a sensor group such as a guide line sensor 16 and a fixed point sensor 17, a steering clutch 18 for switching between manual traveling and automatic traveling, and a throttle. It has various switching mechanisms 20, 21 such as the clutch 19.

The steering driver 10 supplies a drive current corresponding to a steering instruction signal output from the controller 9 to the steering motor 11 during automatic traveling to rotate the steering shaft 22. At this time,
The steering wheel 4 is disengaged from the steering shaft 22 by the steering clutch 18, and manual operation is disabled.

The throttle motor 12 is driven in response to an opening instruction signal output from the controller 9 during automatic traveling, and the throttle clutch 19 is similarly engaged in response to an ON instruction signal output from the controller 9. It At this time, the switching device 21 switches the drive system of the engine 1 from the governor 6 side to the throttle motor 12 side. As a result, during automatic traveling, the throttle opening is adjusted according to the drive amount of the throttle motor 12 instead of the operation amount of the accelerator pedal 5.

The brake motor driver 13 supplies the drive current corresponding to the braking force command value output from the controller 9 to the brake motor 14 during automatic traveling. As a result, the brake motor 14 drives the drum brakes 8a to 8d provided on each of the four wheels 2a to 2d via the gear 23 and the switching mechanism 20 to brake the vehicle. Further, the brake pedal 7 is connected to the drum brakes 8a to 8a through the switching mechanism 20 even during automatic traveling.
It is in a state of being connected to 8d, and braking by manual operation is possible.

The electromagnetic brake 15 is a parking brake device which is on / off controlled by the controller 9, and is spline-fitted to a rotary shaft 24 for transmitting the rotation of the engine 1 to the transmission 3 as shown in the figure. And a fixed plate 15b fixed to the outer wall or the like of the transmission 3 so as not to contact the rotating shaft 24 and to face the disk 15a. Since the disk 15a is spline-fitted to the rotary shaft 24, the disk 15a rotates integrally with the rotary shaft 24 while being movable in the axial direction of the rotary shaft 24. In addition, fixed board 1
5b is composed of a permanent magnet that generates a magnetic field that attracts the disk 15a, and an electromagnet that is excited by the controller 9 so as to cancel the magnetic field of the permanent magnet.

That is, in the electromagnetic brake 15, the excitation of the electromagnet is turned on during traveling, and the magnetic field of the permanent magnet is canceled by this magnetic field, so that the attraction force to the disk 15a is lost, and as a result, the rotary shaft 24 is rotated. On the other hand, braking is no longer effective. On the other hand, if the excitation to the electromagnet is turned off immediately before stopping,
The disk 15a is fixed to the fixed plate 15b by the magnetic force of the permanent magnet.
The rotary shaft 24 is braked.

The guide wire sensor 16 is attached to a T-shaped arm 25 attached to the front end of the vehicle so as to be rotatable in the horizontal direction.
It is placed in three places so as to face the ground. The guide wire sensor 16 magnetically detects a guide wire (not shown) embedded in a golf course or the like, and outputs a detection signal to the controller 9 according to the distance from the guide wire. The controller 9 controls the traveling of the vehicle based on the output of the guide wire sensor 16 so that the vehicle does not depart from the course.

The fixed point sensor 17 is attached to a predetermined position of the vehicle so as to face the ground, and magnetically defines a fixed point composed of a plurality of permanent magnets (not shown) embedded at predetermined intervals in a golf course or the like. To detect. For example, if this fixed point is composed of the magnetic poles of three permanent magnets, and the arrangement thereof is S pole, N pole, and N pole, the fixed point sensor 17
Outputs a detection signal corresponding to the pattern of the arrangement of the magnetic poles to the controller 9. The pattern of the arrangement of the magnetic poles is used as an instruction signal for the controller 9 to control traveling of the vehicle such as stop, start, and speed.

The operation panel 26 is provided near the driver's seat, and in addition to the main switch, a manual / auto switch for instructing switching between manual traveling and automatic traveling, and start / stop for instructing start and stop. It is composed of various switches such as switches and a display section for displaying a warning. When automatic running is selected by the manual / auto switch on the operation panel 26, the controller 9
Switches the traveling mode of the vehicle from manual traveling to automatic traveling, and performs control for automatic traveling described later.

In addition, as a sensor group for detecting the running state of the vehicle, a vehicle speed sensor 30 for detecting a vehicle speed in the transmission 3, a throttle potentiometer 31 for detecting a throttle opening in the engine 1, a steering driver 10 and a brake motor driver 13 are provided. Are the thermistors 32 and 33 that detect the respective temperatures, the brake motor driver 13 is a current sensor 34 that further detects the amount of current supplied to the brake motor 14, and the gear 23 is the brake motor 14 due to an abnormality in the mechanical brake mechanism or the like. A brake limit switch 35 for detecting whether or not the number of revolutions exceeds a certain limit value, and a brake release position detection switch 36 for detecting whether or not a position at which the mechanical brake mechanism is released has been reached.
Are provided respectively.

Configuration of Controller 9 Next, the configuration of the controller 9 will be described. The controller 9 is composed of hardware such as a CPU (central processing unit) and a memory, and its software configuration has a target vehicle speed setting unit 91, a driving force calculation unit 92, a throttle drive calculation, as shown in FIG. Unit 93, braking force calculation unit 94, braking state switching determination unit 95, current command value calculation unit 9
6, excitation voltage calculation unit 97, abnormality determination / abnormality processing unit 98,
It is composed of input interfaces 99a to 99h for receiving various sensor outputs and switch outputs, and output interfaces 99i to 99m for outputting control signals such as various command values to the outside.

The target vehicle speed setting section 91 outputs the set value of the target vehicle speed based on the speed instruction information read from the memory in response to the instruction signal supplied from the fixed point sensor 17 when the operation panel 26 is instructed to start. To do. Driving force calculator 9
2 calculates the necessary driving force to be applied to the vehicle based on the difference between the target vehicle speed setting value and the current vehicle speed detection value output from the vehicle speed sensor 30 installed in the transmission 3.

The throttle drive calculation unit 93 outputs an on / off instruction signal for the throttle clutch 19 according to the running mode, and based on the calculation result of the required drive force and the detection result of the throttle opening degree by the throttle potentiometer 31. A throttle drive pulse corresponding to the drive amount of the throttle motor 12 is output.

The braking force calculation unit 94 calculates the required braking force based on the difference between the target vehicle speed setting value and the current vehicle speed detection value and the amount of current supplied to the brake motor 14 detected by the current sensor 34.

The braking state switching determination unit 95 determines whether or not the braking state is appropriate based on the difference between the set value of the target vehicle speed and the current vehicle speed detection value and the detection result of the throttle opening. The result is output to the braking force calculation unit 94. That is, if the throttle is opened to a certain extent and is in an accelerating state even though the vehicle speed is substantially equal to the target vehicle speed, the balance is maintained by simultaneously accelerating and braking. If this balanced state is left as it is, the fuel is wasted and the brake shoes are worn. Here, a determination is made to escape from such an inappropriate braking state (that is, the above-mentioned balanced state).

The braking force calculation unit 94 outputs the calculated required braking force as it is to the current command value calculation unit 96 if the result of the determination is an appropriate braking state. On the other hand, if the result of the determination is an inappropriate braking state, the required braking force is gradually decreased until it reaches a predetermined value (for example, "0"), and then output to the current command value calculation unit 96.

Further, the braking force calculation unit 94 detects whether or not the brake mechanism is in the brake release position based on the ON / OFF state of the brake release position detection switch 36 when the vehicle is not braked. When the brake mechanism is not in the brake release position, a constant value for rotating the brake motor 14 in the reverse direction to completely release the drum brakes 8a to 8d is output.

The current command value calculation unit 96 includes a braking force calculation unit 9
Based on the value of the required braking force calculated by 4, the braking force command value to be given to the brake motor driver 13 is output. The excitation voltage calculation unit 97 outputs a binary signal that instructs the electromagnetic brake 15 to turn on / off.

The abnormality determination / abnormality processing unit 98 is provided with the temperature detection values of the thermistors 32 and 33 provided in the steering driver 10 and the brake motor driver 13, the output of the brake limit switch 35, the current vehicle speed detection value and the necessary control value. An abnormality determination is made based on the power calculation result. When it is determined that the vehicle is abnormal, a vehicle stop processing instruction is issued. The current command value calculation unit 96, the excitation voltage calculation unit 97, and the throttle drive calculation unit 93 receive the above stop processing instruction and output a value for stopping the vehicle.

(2) Operation of the Embodiment Next, with reference to the flow chart shown in FIG. 3, the operation during automatic traveling according to the present embodiment will be described.

Normal Braking Control Operation First, a normal braking control operation except for the braking control for breaking out of the above-mentioned balanced state will be described. In FIG.
First, the controller 9 determines whether or not the vehicle is parked (step Sa1). After the determination result is “No”, the process proceeds to step Sa2.

In step Sa2, the current throttle opening is in an accelerating state (that is, an opening larger than an idle opening + α which is an opening where the clutch of the automatic transmission is not disengaged), and the vehicle speed is the target vehicle speed. (Target vehicle speed + offset value ΔV ₀ (for example, 0.5 km / h))
Within the range). That is,
Here, it is detected whether or not the above-mentioned balanced state in which acceleration and braking are simultaneously performed.

In this case, since the normal braking control is performed, the result of the determination in step Sa2 is "No", and the process proceeds to step Sa3. In step Sa3, the necessary braking force F is calculated as follows in order to perform the braking control by PID based on the difference Δv between the current vehicle speed detection value and the target vehicle speed.

That is, the required braking force F is given as a function F = f (Δv) of the vehicle speed difference Δv, and the required braking force F (n−1) in the previous control cycle and the required braking force F in the present control cycle are given. If the difference from (n) is set to ΔF,
ΔF is given by the following equation (1). ΔF = Kp × (Δv (n) -Δv (n-1)) + Ki × Δv (n) + Kd × (Δv (n) -2Δv (n-1) + Δv (n-2)) (1) , Δv (n) is the vehicle speed difference in the current control cycle, Δv (n-1) is the vehicle speed difference in the previous control cycle, Δv (n-2) is the vehicle speed difference in the control cycle two times before, and Kp, Ki, Kd are It is a predetermined constant.

When the required braking force F is calculated, the process proceeds to step Sa4 (see FIG. 3). In step Sa4, it is determined whether or not the calculation result of the required braking force F is a negative value. Here, if the calculated required braking force F is a positive value,
The result of this determination is "No", and the flow proceeds to step Sa5.

In step Sa5, the magnitude of the running load L of the vehicle is determined based on the engine speed, the gear ratio (ratio between the engine speed and the vehicle speed) and the magnitude of the braking force currently applied. Here, the traveling load L means a resistance that tends to hinder the traveling of the vehicle, and is small when traveling downhill or when the vehicle weight is light, while it is traveling uphill or when the vehicle weight is heavy. Sometimes it becomes big.

In step Sa5, when both the engine speed and the gear ratio exceed a predetermined threshold value, it is determined that the load is high, the braking force currently applied exceeds the predetermined threshold value, and the gear ratio is exceeded. Is lower than a predetermined threshold value, it is determined to be low load, and otherwise is determined to be medium load.

Next, when proceeding to step Sa6, the rotation direction of the brake motor 14 is set to the braking direction. The braking is released by rotating the brake motor 14 in the opposite direction, which will be described later. And step S
When the process proceeds to a7, the brake motor driver 13 is calculated based on the calculation result of the required braking force F in step Sa3 described above.
The braking force command value G for the is calculated.

This braking force command value G is the required braking force F mentioned above.
Is multiplied by a predetermined coefficient k. However, for the reason described later, when the acceleration of the vehicle is positive, the braking force command value G is a function G = g (F, L) of the required braking force F and the running load L of the vehicle.
Given as. The following equations (2) to (4) are equations for calculating the braking force command value G corresponding to the magnitude of the traveling load L. G = k × F + C1 (when L is low load) …………………………………… (2) G = k × F + C2 (when L is medium load) …………………… …………………… (3) G = k × F + C3 (when L is high load) ……………………………… (4) However, k is a predetermined coefficient, C1, C2 and C3 are different constants, and 0 <C1 <C2 <C3 holds.

When the acceleration of the vehicle is positive, constants C1, C2 and C3 (C1 <C2 <C are set according to the magnitude of the traveling load L).
The reason why 3) is added to the braking force command value G is based on the following reason. That is, when starting the braking from the non-braking state, the brake motor 14 needs to supply a large current at the first energization due to the characteristics of the motor itself and the friction resistance of the power transmission system path to the drum brakes 8a to 8d. Because there is.

That is, in the case of low load (for example, during downhill)
Since it is already energized and braking the motor, it is not necessary to increase C1, but in the case of high load (for example, when going up)
Is a non-braking state (that is,
Since the motor is not energized), it is necessary to increase C3 when starting energization.

In step Sa8, the braking force command value G calculated in step Sa7 is supplied to the brake motor driver 13 to drive the brake motor 14. As a result, the vehicle is braked by the braking force corresponding to the braking force command value G.

Braking control operation for breaking out of the balanced state Next, the braking control operation for breaking out of the balanced state will be described. In this case, acceleration and braking are being performed at the same time when the vehicle speed substantially matches the target vehicle speed, so the result of the determination in step Sa2 is "Yes", and the process proceeds to step Sa9. In step Sa9, the current required braking force F is decreased by a constant value c in order to get out of this balanced state. That is, this step Sa
The required braking force F is gradually reduced by repeatedly executing 9. Along with this, the throttle opening is also gradually reduced so that the vehicle speed matches the target vehicle speed. After the required braking force F is calculated as described above, steps Sa4 to Sa8 described above are executed to drive the brake motor 14 to apply braking, as in the case of normal braking control.

Here, when the vehicle enters a downhill from a flat road or enters a flat road from an uphill, it is easy to fall into the above-mentioned balanced state. Therefore, in order to escape from the balanced state by using these cases as concrete examples. The operation of will be described.

FIG. 4 shows changes in vehicle speed difference (vehicle speed-target vehicle speed), throttle opening and required braking force when the vehicle enters a downhill from a flat road. In this figure, when the vehicle starts to enter a downhill from a flat road, the traveling speed of the vehicle decreases and the vehicle speed difference increases (see P in the figure).
1). As the vehicle speed difference increases, the command value of the throttle opening is decreased (P2 in the figure) and the required braking force F calculated by the above equation (1) is increased (P3 in the figure).
When the vehicle speed difference starts to decrease (P4 in the figure), the required braking force F starts to decrease accordingly (P5 in the figure). The braking control at this time is based on the above equation (1).

In this way, when the vehicle speed difference further decreases and the vehicle speed difference falls within the range of the offset value ΔV ₀ (P6 in the figure), the throttle opening at this time is larger than the idle opening + α (P7 in the figure). It is considered that the balance state has been reached, and thereafter, the required braking force F is decreased by a constant value c (P8 in the figure). Along with this, the throttle opening is also gradually reduced (P9 in the figure).

When the throttle opening decreases as the required braking force F decreases and falls below the idle opening + α (P10 in the figure), the control for reducing the required braking force F by a constant value c is stopped. Then, the braking control based on the above equation (1) is started again (P11 in the figure). In this case, since the vehicle is traveling downhill, the required braking force F does not become "0" and maintains a certain value.

FIG. 5 shows changes in the vehicle speed difference, the throttle opening, and the required braking force when the vehicle enters an uphill on a flat road. In this case as well, the traveling load decreases as the vehicle enters an uphill onto a flat road, and the vehicle speed difference increases (P1 'in the figure). Accordingly, as in the case of FIG. 4, the throttle opening is reduced (P2 ′ in the figure),
The required braking force F is increased (P3 'in the figure). When the vehicle speed difference starts to decrease (P4 'in the figure), the required braking force F is decreased (P5' in the figure). The braking control at this time is the above formula
It is based on (1).

When the vehicle speed difference falls within the range of the offset value ΔV ₀ (P6 'in the drawing), the throttle opening at this time is larger than the idle opening + α (P in the drawing).
7 '), as in the case of FIG. 4, it is considered that the above-mentioned equilibrium state has been reached, and thereafter, the required braking force F is decreased by a constant value c (P8' in the figure). Along with this, the throttle opening is also gradually reduced (P9 'in the figure).

After that, since the vehicle travels on a flat road, the throttle opening is maintained at a value larger than the idle opening + α (P10 'in the figure), so that the required braking force F continues to decrease by a constant value c. Finally, since it becomes a negative value, it is set to the value "0" (P11 'in the drawing).

Operation When Braking Force Is Unnecessary When the braking force is not required means when the vehicle is parked (that is, parking by the electromagnetic brake 15) and when the vehicle is run without braking. There are two cases. First, when the vehicle is parked, the above-mentioned step Sa1
The determination result (see FIG. 3) is “Yes”, and the process proceeds to step Sa10. In step Sa10, since the parking braking force is applied by the electromagnetic brake 15 during parking, it is not necessary to drive the brake motor 14, so the required braking force F is set to "0". And it progresses to step Sa12 mentioned later.

On the other hand, when traveling without braking,
The calculation result of the required braking force F in steps Sa3 and Sa9 described above becomes smaller than "0". Therefore, the result of the determination in step Sa4 described above is "Yes", and the process proceeds to step Sa11. In step Sa11, since there is no negative braking force, the required braking force F is set to "0", and the process proceeds to the next step Sa12.

In step Sa12, it is determined whether the brake release position detection switch 36 is on. That is, the brake mechanism that drives the drum brakes 8a to 8d is provided with a return spring (not shown) and is configured to automatically return when the brake motor 14 is not braked. It may not return to the release position. Therefore, the brake release position detection switch 36 that is turned on when the brake mechanism returns to the brake release position is set to the gear 23.
It is provided at a predetermined location such as, and the on / off state is detected here.

If the brake mechanism has not returned to the brake release position, the result of the determination in step Sa12 is "No", and the process proceeds to step Sa13. In step Sa13, the rotation direction of the brake motor 14 is set to the opposite direction to the braking direction in order to return the brake mechanism to the brake release position. Then, in step Sa14, the braking force command value G is set to a value (constant value) necessary for releasing the brake.
And the brake motor 14 is driven in the opposite direction. As a result, the brake mechanism is reliably returned to the brake release position.

On the other hand, when the brake mechanism has already returned to the brake release position, the determination result of the above step Sa12 is "Yes", and the routine proceeds to step Sa15. In step Sa15, it is not necessary to drive the brake motor 14 in the reverse direction, so the braking force command value G is set to "0". As a result, the brake motor 14 is not driven.

(3) Summary In this way, when the vehicle speed detection value is fed back to control the throttle opening and the braking force to match the vehicle speed with the target vehicle speed, the acceleration and the braking are performed simultaneously. The vehicle speed may be in a balanced state in which the vehicle speed matches the target vehicle speed, but in the present embodiment, such a balanced state is detected, and in order to escape from this state, the vehicle speed difference (vehicle speed detection value-target Stop braking control based on vehicle speed),
The braking force currently being applied is gradually reduced. Along with this, the throttle opening is also gradually reduced so that the vehicle speed matches the target vehicle speed, and it becomes possible to escape from the balanced state.

(4) Modification Example In the above-described embodiment, the running load L is detected by the engine speed or the gear ratio, but the invention is not limited to such a detection method, and for example, an inclination angle sensor ( (Not shown)
You may make it detect using. In this case, for example, when the inclination angle is + 12 ° (up), it is determined that the load is high, and -1
It is possible to determine that the load is low at 2 ° (downhill). In the embodiment, the reason why the running load L is detected by the engine speed and the gear ratio is that it does not change only when the running load L goes up and down the slope, but other factors such as vehicle weight and engine performance. This may change depending on the situation.

[0057]

As described above, according to the present invention, it is possible to get out of the equilibrium state in which acceleration and braking are continuously performed unnecessarily simultaneously even though the vehicle speed matches the target vehicle speed. Therefore, waste of fuel and wear of the brake shoes can be prevented.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of an automatic vehicle according to an embodiment.

FIG. 2 is a block diagram showing a software configuration of a controller of the autonomous vehicle.

FIG. 3 is a flowchart for explaining the operation of the embodiment.

FIG. 4 is a graph for explaining the operation of the embodiment when a vehicle enters a downhill from a flat road.

FIG. 5 is a graph for explaining the operation of the embodiment when the vehicle enters a flat road from an uphill road.

[Explanation of symbols]

 9 ... Controller (detection means, braking force reducing means), 10 ... Steering driver, 11 ... Steering motor, 12 ... Throttle motor, 13 ... Brake motor driver, 14 ... Brake motor, 15 ... Electromagnetic brake, 30 ... Vehicle speed sensor (detection) Means), 31 ... Throttle potentiometer (detection means), 36 ... Brake release position detection switch 91 ... Target vehicle speed setting unit, 92 ... Driving force calculation unit, 93 ... Throttle drive calculation unit, 94 ... Braking force calculation unit, 95 ... Braking State switching determination unit, 96 ... Current command value calculation unit, 97 ... Excitation voltage calculation unit, 98 ... Abnormality determination / abnormality processing unit, 99a to 99m ... Interface.

Claims (2)

[Claims] 1. An automatic traveling vehicle in which a vehicle speed control is performed by controlling a throttle opening and a braking force so that the vehicle speed detection value matches a target vehicle speed, and the vehicle speed detection value is substantially equal to the target vehicle speed by performing acceleration and braking at the same time. Detecting means for detecting a matching balanced state, and when the balanced state is detected by the detecting means,
An automatic traveling vehicle comprising: a braking force reducing means for gradually reducing the braking force by a predetermined amount. 2. The detecting means detects the balance state by determining whether the vehicle speed detection value is substantially equal to the target vehicle speed and whether the throttle opening is larger than a predetermined opening. The automatic vehicle according to claim 1, wherein the automatic vehicle is a vehicle.