JP3685343B2 - Self-driving car - 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

[0001]
[Industrial application fields]
The present invention relates to an automatic traveling vehicle that performs speed control during traveling by controlling a throttle opening and a braking force, respectively.
[0002]
[Prior art]
2. Description of the Related Art Various types of automatic traveling vehicles have been developed that are used as golf carts for carrying luggage and people such as golf bags in golf courses. As this type of automatic traveling vehicle, for example, one disclosed in JP-A-5-73144 is known. In the automatic traveling 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]
[Problems to be solved by the invention]
By the way, in the automatic traveling vehicle disclosed in the above publication, since the throttle opening and the braking force of regenerative braking are controlled independently, acceleration and braking are performed with the throttle opened to some extent while applying regenerative braking. The vehicle speed may match the target vehicle speed. In such a case, since acceleration and braking are continuously performed at the same time, fuel is wasted and the brake shoe is also worn unnecessarily.
[0004]
The present invention has been made under such a background, and provides an automatic traveling vehicle that can prevent waste of fuel and wear of brake shoes due to continuous acceleration and braking. It is aimed.
[0005]
[Means for Solving the Problems]
According to the first aspect of the present invention, in an automatic traveling vehicle that performs vehicle speed control by independently controlling the throttle opening and the braking force based on the difference between the vehicle speed detection value and the target vehicle speed, the vehicle speed detection value and the target vehicle speed are controlled. Detecting means for detecting a vehicle speed difference between the vehicle speed difference and the vehicle speed difference during a period when the vehicle speed difference is greater than a predetermined positive value. Required braking force according to While the vehicle speed difference is Less than the predetermined positive value And a braking force control means for providing a braking force obtained by gradually reducing the necessary braking force during a period in which the current throttle opening is larger than a predetermined value. Yes.
[0007]
[Action]
According to this invention, the detecting means detects the balanced state in which the vehicle speed detection value substantially matches the target vehicle speed by performing acceleration and braking simultaneously, and the braking force reducing means detects the balanced state by the detecting means. At this time, the braking force is gradually decreased by a predetermined amount.
[0009]
【Example】
Embodiments of the present invention will be described below with reference to the drawings.
(1) Configuration of the embodiment
(1) Configuration of autonomous vehicle
FIG. 1 is a block diagram showing the configuration of an autonomous vehicle according to one embodiment of the present invention. The automatic traveling 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 like an ordinary automobile, and from this engine 1 via a V-belt type automatic transmission 1a. A transmission 3 for transmitting the supplied driving force to the rear wheels 2a and 2b, which are driving wheels, a handle 4 for steering the front wheels 2c and 2d, and an accelerator pedal 5 for adjusting the throttle opening to change the vehicle speed And a governor 6, a brake pedal 7 for braking the vehicle, and mechanical brake mechanisms such as drum brakes 8a to 8d.
[0010]
Further, the automatic traveling vehicle is capable of automatic traveling as well as traveling by normal manual operation (hereinafter referred to as manual traveling), and a controller 9, a steering driver 10, and a steering motor 11 that perform control for the automatic traveling. , A throttle motor 12, a brake motor driver 13, a brake motor 14, an electromagnetic brake 15, and other sensor groups such as a guide wire sensor 16 and a fixed point sensor 17, a steering clutch 18 for switching between manual travel and automatic travel, a throttle clutch 19, etc. The various switching mechanisms 20 and 21 are provided.
[0011]
The steering driver 10 supplies a drive current corresponding to the steering instruction signal output from the controller 9 during automatic traveling to the steering motor 11 to rotate the steering shaft 22. At this time, the handle 4 is disconnected from the steering shaft 22 by the steering clutch 18, and manual operation is disabled.
[0012]
The throttle motor 12 is driven in accordance with an opening instruction signal output from the controller 9 during automatic traveling, and the throttle clutch 19 is similarly connected in response to an on instruction signal output from the controller 9. 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 rather than the operation amount of the accelerator pedal 5.
[0013]
The brake motor driver 13 supplies a drive current corresponding to a braking force command value output from the controller 9 during automatic traveling to the brake motor 14. Thus, the brake motor 14 drives the drum brakes 8a to 8d provided on 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 8d via the switching mechanism 20 even during automatic traveling, and braking by manual operation is possible.
[0014]
The electromagnetic brake 15 is a parking brake device that is on / off controlled by the controller 9. As shown in the figure, the electromagnetic brake 15 is a disc 15 a that is spline-fitted to a rotating shaft 24 that transmits the rotation of the engine 1 to the transmission 3. And a stationary platen 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 15 a is spline-fitted to the rotating shaft 24, the disk 15 a rotates integrally with the rotating shaft 24, while being movable in the axial direction of the rotating shaft 24. The fixed platen 15b includes 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.
[0015]
In other words, the electromagnetic brake 15 is energized with respect to the electromagnet during running, and the magnetic field of the permanent magnet is canceled by this magnetic field, so that there is no attracting force to the disk 15a. As a result, the rotating shaft 24 is braked. It is supposed to stop working. On the other hand, when the excitation with respect to the electromagnet is turned off immediately before the stop, the disk 15a is attracted to the fixed platen 15b by the magnetic force of the permanent magnet, and the rotating shaft 24 is braked.
[0016]
The guide wire sensor 16 is arranged at three positions on a T-shaped arm 25 attached to the front end portion of the vehicle so as to be rotatable in the horizontal direction so as to face the ground. The guide wire sensor 16 magnetically detects a guide wire (not shown) embedded in a course of a golf course and outputs a detection signal corresponding to the distance to the guide wire to the controller 9. Based on the output of the guide wire sensor 16, the controller 9 controls traveling so that the vehicle does not deviate from the course.
[0017]
The fixed point sensor 17 is attached to a predetermined position of the vehicle so as to face the ground, and magnetically detects a fixed point composed of a plurality of permanent magnets (not shown) embedded at a predetermined interval in a golf course course or the like. For example, if this fixed point is constituted by magnetic poles of three permanent magnets and the arrangement thereof is S pole, N pole, N pole, the fixed point sensor 17 sends a detection signal corresponding to the arrangement pattern of the magnetic poles to the controller 9. Output to. The arrangement pattern of the magnetic poles is used as an instruction signal for controlling the vehicle 9 to stop, start, and speed the vehicle.
[0018]
The operation panel 26 is provided in the vicinity of the driver's seat, and includes a main switch, a manual / auto switch for instructing switching between manual travel and automatic travel, and a start / stop switch for instructing start and stop. It is comprised by the display part which performs various switches and warning display. When automatic travel is selected by the manual / auto switch on the operation panel 26, the controller 9 switches the travel mode of the vehicle from manual travel to automatic travel, and performs control for automatic travel described later.
[0019]
In addition, as a sensor group for detecting the running state of the vehicle, the transmission 3 has a vehicle speed sensor 30 for detecting the vehicle speed, the engine 1 has a throttle potentiometer 31 for detecting the throttle opening, the steering driver 10 and the brake motor driver 13 have The thermistors 32 and 33 for detecting the temperature of the motor, the current sensor 34 for detecting the amount of current supplied to the brake motor 14 for the brake motor driver 13, and the rotational speed of the brake motor 14 for the gear 23 due to an abnormality in the mechanical brake mechanism or the like. A brake limit switch 35 for detecting whether or not a certain limit value has been exceeded and a brake release position detection switch 36 for detecting whether or not the mechanical brake mechanism has been released are provided.
[0020]
(2) Configuration of controller 9
Next, the configuration of the controller 9 will be described. The controller 9 is configured by hardware such as a CPU (Central Processing Unit) and a memory. As shown in FIG. 2, the software configuration includes a target vehicle speed setting unit 91, a driving force calculation unit 92, a throttle drive calculation. Unit 93, braking force calculation unit 94, braking state switching determination unit 95, current command value calculation unit 96, excitation voltage calculation unit 97, abnormality determination / abnormality processing unit 98, input interfaces 99 a to 99 h for capturing various sensor outputs and switch outputs And output interfaces 99i to 99m for outputting control signals such as various command values to the outside.
[0021]
When a start is instructed on the operation panel 26, the target vehicle speed setting unit 91 outputs a set value of the target vehicle speed based on the speed instruction information read from the memory in accordance with the instruction signal supplied from the fixed point sensor 17.
The driving force calculation unit 92 calculates the necessary driving force to be applied to the vehicle based on the difference between the set value of the target vehicle speed and the current vehicle speed detection value output from the vehicle speed sensor 30 installed in the transmission 3.
[0022]
The throttle drive calculation unit 93 outputs an on / off instruction signal for the throttle clutch 19 according to the travel mode, and the throttle motor 12 based on the calculation result of the required driving force and the detection result of the throttle opening by the throttle potentiometer 31. The throttle drive pulse corresponding to the drive amount is output.
[0023]
The braking force calculation unit 94 calculates the necessary braking force based on the difference between the set value of the target vehicle speed and the current vehicle speed detection value and the amount of current supplied to the brake motor 14 detected by the current sensor 34.
[0024]
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 braking state switching determination unit 95 determines whether or not the braking state is appropriate and controls the determination result. Output to the power calculator 94. In other words, if the throttle is opened to a certain extent and the vehicle is in an acceleration state even though the vehicle speed is substantially equal to the target vehicle speed, the balance is maintained by performing acceleration and braking simultaneously. If this balanced state is left unattended, fuel will be wasted and brake shoes will be worn. Here, a determination is made to escape from such an improper braking state (that is, the balanced state).
[0025]
If the determination result is an appropriate braking state, the braking force calculation unit 94 outputs the calculated required braking force to the current command value calculation unit 96 as it is. On the other hand, if the determination result is an inappropriate braking state, the required braking force is output to the current command value calculation unit 96 while gradually decreasing until a required braking force reaches a predetermined value (for example, “0”).
[0026]
In addition, 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 is output to completely release the drum brakes 8a to 8d.
[0027]
The current command value calculation unit 96 outputs a braking force command value to be given to the brake motor driver 13 based on the necessary braking force value calculated by the braking force calculation unit 94.
The excitation voltage calculator 97 outputs a binary signal that instructs the electromagnetic brake 15 to turn on / off.
[0028]
The abnormality determination / abnormality processing unit 98 calculates 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 braking force, respectively. Based on the result, abnormality determination is performed. And when it determines with it being abnormal, the stop process instruction | indication of a vehicle is issued. The current command value calculation unit 96, the excitation voltage calculation unit 97, and the throttle drive calculation unit 93 receive the stop processing instruction and output a value for stopping the vehicle.
[0029]
(2) Operation of the embodiment
Next, with reference to the flowchart shown in FIG. 3, the operation | movement at the time of automatic driving | running | working by a present Example is demonstrated.
[0030]
(1) Normal braking control operation
First, a normal braking control operation excluding the braking control for getting out of the balance state will be described. In FIG. 3, the controller 9 first determines whether or not the vehicle is parked (step Sa1). After the determination result is “No”, the process proceeds to step Sa2.
[0031]
In step Sa2, the current throttle opening is in an acceleration state (that is, an opening larger than the idle opening + α, which is an opening at which the clutch of the automatic transmission is not disengaged), and the vehicle speed is substantially equal to the target vehicle speed. State (target vehicle speed + offset value ΔV ₀ It is determined whether or not (for example, within a range of 0.5 km / h). In other words, here, it is detected whether or not the above-described balance state in which acceleration and braking are performed simultaneously.
[0032]
In this case, since it is normal braking control, the determination result 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 braking control by PID based on the difference Δv between the current vehicle speed detection value and the target vehicle speed.
[0033]
That is, the necessary braking force F is given as a function F = f (Δv) of the vehicle speed difference Δv, and the necessary braking force F (n−1) in the previous control cycle and the necessary braking force F (n) in the current control cycle. 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)
Where 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 previous control cycle,
Kp, Ki, Kd are predetermined constants.
[0034]
When the necessary 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 necessary braking force F is a negative value. If the calculated necessary braking force F is a positive value, the determination result is “No”, and the process proceeds to step Sa5.
[0035]
In step Sa5, the magnitude of the running load L of the vehicle is determined based on the engine speed, the gear ratio (the ratio between the engine speed and the vehicle speed) and the magnitude of the braking force currently applied.
Here, the traveling load L means resistance that hinders traveling of the vehicle, and becomes small when traveling on a downhill or when the vehicle weight is light, while it is small when traveling on an uphill or when the vehicle is heavy. Sometimes it gets big.
[0036]
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 currently applied braking force exceeds the predetermined threshold value, and the gear ratio is predetermined. When it falls below the threshold value, it is determined that the load is low, and in other cases, it is determined that the load is medium.
[0037]
Next, in step Sa6, the rotation direction of the brake motor 14 is set to the braking direction. The braking is released when the brake motor 14 is rotated in the reverse direction, which will be described later.
Then, when the process proceeds to step Sa7, a braking force command value G to the brake motor driver 13 is calculated based on the calculation result of the necessary braking force F in step Sa3.
[0038]
The braking force command value G is given by multiplying the necessary braking force F by a predetermined coefficient k. However, for reasons to be described later, when the acceleration of the vehicle is positive, the braking force command value G is given as a function G = g (F, L) of the required braking force F and the traveling load L of the vehicle. The following formulas (2) to (4) are formulas for calculating the braking force command value G corresponding to the magnitude of the traveling load L, respectively.
G = k × F + C1 (when L is lightly loaded) ……………………………… (2)
G = k × F + C2 (when L is medium load) ……………………………… (3)
G = k × F + C3 (when L is under high load) ……………………………… (4)
Where k is a predetermined coefficient,
C1, C2, C3 are different constants,
And 0 <C1 <C2 <C3 is established.
[0039]
When the acceleration of the vehicle is positive, the constants C1, C2, C3 (C1 <C2 <C3) are added to the braking force command value G according to the magnitude of the traveling load L for the following reason. . That is, when starting 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 frictional resistance of the power transmission path to the drum brakes 8a to 8d. Because there is.
[0040]
In other words, when the load is low (for example, when going down), it is not necessary to increase C1 because the motor is already energized and braking, but when the load is high (for example, when going up), the traveling acceleration is positive. Since it is in a non-braking state (that is, a state where no power is supplied to the motor) before starting, it is necessary to increase C3 when starting the power supply.
[0041]
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.
[0042]
(2) Braking control operation to escape from the balanced state
Next, a braking control operation for getting out of the above-described balanced state will be described. In this case, since the vehicle speed is substantially equal to the target vehicle speed and acceleration and braking are being performed at the same time, the determination result 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 escape from this balanced state. That is, the necessary braking force F is gradually reduced by repeatedly executing Step Sa9. Accordingly, the throttle opening is also gradually reduced so that the vehicle speed matches the target vehicle speed. After calculating the necessary braking force F as described above, the steps Sa4 to Sa8 are executed as in the case of normal braking control, and the brake motor 14 is driven to apply the braking.
[0043]
Here, when a vehicle enters a downhill from a flat road or when entering a flat road from an uphill, the above-described balanced state is likely to occur. explain.
[0044]
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 vehicle speed difference increases because the traveling load of the vehicle decreases (P1 in the figure). In response to the increase in the vehicle speed difference, the throttle opening command value 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).
[0045]
Thus, the vehicle speed difference further decreases, and the vehicle speed difference becomes the offset value ΔV. ₀ (P6 in the figure), since the throttle opening at this time is larger than the idle opening + α (P7 in the figure), it is considered that the above-mentioned balanced state has been reached. Decrease by c (P8 in the figure). Along with this, the throttle opening is gradually reduced (P9 in the figure).
[0046]
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 decreasing the required braking force F by a constant value c is stopped and again increased. The braking control based on the formula (1) is started (P11 in the figure). In this case, since the vehicle is traveling on the downhill, the required braking force F does not become “0”, but maintains a certain value.
[0047]
FIG. 5 shows changes in the vehicle speed difference, the throttle opening, and the required braking force when the vehicle enters the flat road from the uphill. In this case as well, the traveling load decreases as the vehicle enters the flat road from the uphill, and thus 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), and the required braking force F is increased (P3 ′ in the figure). When the vehicle speed difference starts to decrease (P4 ′ in the figure), the necessary braking force F is decreased (P5 ′ in the figure). The braking control at this time is based on the above equation (1).
[0048]
And the vehicle speed difference is offset value ΔV ₀ (P6 ′ in the figure), since the throttle opening at this time is larger than the idle opening + α (P7 ′ in the figure), as in the case of FIG. Thereafter, the necessary braking force F is decreased by a constant value c (P8 ′ in the figure). Along with this, the throttle opening is gradually reduced (P9 'in the figure).
[0049]
Thereafter, since the vehicle travels on a flat road, the throttle opening degree is maintained at a value larger than the idle opening degree + α (P10 ′ in the figure), so that the necessary braking force F continues to be decreased by a constant value c. Since it is a negative value, the value is set to “0” (P11 ′ in the drawing).
[0050]
(3) Operation when braking force is not required
When the braking force is unnecessary, there are two cases where the vehicle is parked (that is, parking by the electromagnetic brake 15) and when the vehicle travels without braking.
First, when the vehicle is parked, the determination result of step Sa1 (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, there is no need to drive the brake motor 14, so the necessary braking force F is set to “0”. Then, the process proceeds to Step Sa12 described later.
[0051]
On the other hand, when traveling without braking, the calculation result of the necessary braking force F in steps Sa3 and Sa9 is smaller than “0”. Therefore, the determination result in step Sa4 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.
[0052]
In step Sa12, it is determined whether or not the brake release position detection switch 36 is on. That is, the brake mechanism for driving the drum brakes 8a to 8d is provided with a return spring (not shown) and is configured to return automatically when the brake motor 14 is not braked. It may not return to the release position. For this reason, a brake release position detection switch 36 that is turned on when the brake mechanism returns to the brake release position is provided at a predetermined location such as the gear 23, and the on / off state is detected here.
[0053]
Here, when the brake mechanism has not returned to the brake release position, the determination result in Step Sa12 is “No”, and the process proceeds to Step Sa13. In step Sa13, in order to return the brake mechanism to the brake release position, the rotation direction of the brake motor 14 is set in the direction opposite to the braking direction. In step Sa14, the braking force command value G is set to a magnitude (constant value) necessary for releasing the brake, and the brake motor 14 is driven in the reverse direction. As a result, the brake mechanism is reliably returned to the brake release position.
[0054]
On the other hand, if the brake mechanism has already returned to the brake release position, the determination result in Step Sa12 is “Yes”, and the process proceeds to Step Sa15. In step Sa15, since it is not necessary to drive the brake motor 14 in the reverse direction, the braking force command value G is set to “0”. As a result, the brake motor 14 is not driven.
[0055]
(3) Summary
As described above, when the throttle opening and the braking force are controlled by feeding back the detected vehicle speed value so that the vehicle speed matches the target vehicle speed, the vehicle speed matches the target vehicle speed while acceleration and braking are performed simultaneously. In this embodiment, in order to detect such a balanced state and escape from this state, the braking control based on the vehicle speed difference (vehicle speed detection value−target vehicle speed) up to that point is performed. Stop and gradually reduce the braking force currently applied. Along with this, the throttle opening is gradually reduced so that the vehicle speed matches the target vehicle speed, and it is possible to escape from the balanced state.
[0056]
(4) Example of change
In the embodiment described above, the traveling load L is detected by the engine speed and the gear ratio. However, the present invention is not limited to such a detection method, and is detected by using, for example, an inclination angle sensor (not shown). You may do it. In this case, for example, when the inclination angle is + 12 ° (up), it can be determined that the load is high, and when it is −12 ° (down), it can be determined that the load is low. In the embodiment, the detection of the traveling load L based on the engine speed and the gear ratio does not change only when the traveling load L goes up and down the hill, but other factors such as vehicle weight and engine performance. This is because it may change depending on the case.
[0057]
【The invention's effect】
As described above, according to the present invention, it is possible to escape from the balanced state in which acceleration and braking are continuously performed unnecessarily even though the vehicle speed matches the target vehicle speed. It is possible to prevent waste and wear of the brake shoe.
[Brief description of the drawings]
FIG. 1 is a block diagram illustrating a configuration of an automatic traveling vehicle according to an embodiment.
FIG. 2 is a block diagram showing a software configuration of a controller of the automatic traveling 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 the 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.
[Explanation of symbols]
9: Controller (detection means, braking force reduction 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 section,
92 ... Driving force calculation unit,
93 ... Throttle drive calculation unit,
94 ... braking force calculation section,
95 ... Brake state switching determination unit,
96 ... Current command value calculation section,
97 ... Excitation voltage calculator,
98 ... Abnormality determination / abnormality processing unit,
99a-99m ... interface.

Claims (1)

In an autonomous vehicle that performs vehicle speed control by independently controlling the throttle opening and braking force based on the difference between the vehicle speed detection value and the target vehicle speed,
Detection means for detecting a vehicle speed difference between the vehicle speed detection value and the target vehicle speed;
While the vehicle speed difference is greater than a predetermined positive value, the required braking force according to the vehicle speed difference is provided, while the vehicle speed difference is equal to or less than the predetermined positive value , and An automatic traveling vehicle comprising braking force control means for applying a braking force obtained by gradually reducing the necessary braking force during a period in which the current throttle opening is larger than a predetermined value.

Images