JP2002229645A - Control method for automatic traveling vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve reliability of an obstacle detecting sensor 36 provided to prevent a collision of an automatic traveling vehicle. SOLUTION: As the obstacle detecting sensor 36, an ultrasonic sensor is used, and an area in front of the automatic traveling vehicle is divided into three areas of a stop area 44, a speed reduction area 45 and an estimation area 46 in response to a distance from the automatic traveling vehicle. When an obstacle exists in the speed reduction area 45, speed of the automatic traveling vehicle is reduced for traveling, and when the obstacle exists in the stop area 44, the automatic traveling vehicle is stopped, and when the obstacle does not exist within the speed reduction area 45, the automatic traveling vehicle is made to travel at an ordinary speed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an automatic traveling vehicle traveling on a predetermined track along a guide line.

[0002]

2. Description of the Related Art Recently, a battery-powered riding golf cart that transports a player and a golf bag in a golf course has been used as an automatic traveling vehicle. In addition, the demand for a battery-type riding golf cart is increasing in Japan because it has characteristics that it does not emit noise and exhaust gas and is environmentally friendly.

[0003] These battery-powered riding golf carts are:
It is designed to be able to run automatically in a golf course so that you can play yourself without a caddy. That is, a guide line is buried in advance in a cart running path in a golf course, and a low-frequency alternating current is caused to flow through the guide line to generate a magnetic field around the guide line. Then, the generated magnetic field is detected by the induction sensors 16a and 16b installed in the battery-type riding golf cart, and the steering mechanism 25 is operated by moving the steering motor 12, thereby moving the battery-type riding golf cart along the cart running path. This method is generally called an electromagnetic induction method (FIG. 2,
3). In a place where there is no guide line, manual operation using the steering handle 7 is also possible.

As disclosed in Japanese Patent Application Laid-Open No. 9-93703, the electromagnetic induction type golf cart prevents collision with an obstacle such as another golf cart or a golfer running ahead. Therefore, an obstacle detection sensor 36 is provided. When a golfer or the like enters the golf cart immediately before the traveling golf cart, it is necessary to stop the golf cart urgently to prevent collision with the golfer.

[0005]

Generally, an obstacle detection range using an obstacle detection sensor is set in accordance with a braking distance of a golf cart. However, as shown in FIG. 3, the detection range of the obstacle detection sensor increases as the distance increases, so that a fixed obstacle 42 (FIG. 3) such as a standing tree or a fence that does not hinder running is erroneously detected. Emergency stoppages of golf carts were also permitted.

[0006] In addition, even if an indefinite obstacle 43 (Fig. 3) such as a golfer enters the traveling course while confirming safety, the golf cart is stopped urgently and the golfer restarts. There was trouble such as having to put on.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-described problems, and has been made to improve the reliability of an obstacle detection sensor installed for the purpose of preventing a collision of an autonomous vehicle such as a golf cart. It is to make it.

[0008]

In order to solve the above-mentioned problems, a first aspect of the present invention is to provide an automatic traveling vehicle having an obstacle detection sensor for detecting an obstacle existing in front of the automatic traveling vehicle. In the control method, the area in front of the self-driving vehicle is divided into at least three types of areas, a stop area, a deceleration area, and a prediction area, in accordance with the distance from the self-driving car. When the vehicle is present in the stop area, the automatic traveling vehicle is stopped.

According to a second aspect of the present invention, there is provided a control system of an automatic traveling vehicle having an obstacle detection sensor for detecting an obstacle existing in front of the automatic traveling vehicle, wherein the area in front of the automatic traveling vehicle is According to the distance from the autonomous vehicle, at least three types of areas, a stop area, a deceleration area, and a prediction area are divided in this order, and when the obstacle is present in the deceleration area, the autonomous vehicle is divided. If the obstacle is present in the stop area, the automatic traveling vehicle is stopped.If the obstacle is not present in the deceleration area, the automatic traveling vehicle is moved at a normal speed. It is characterized by being driven by.

According to a third aspect of the present invention, there is provided a control system of an automatic traveling vehicle having an obstacle detection sensor for detecting an obstacle present in front of the automatic traveling vehicle, wherein the area in front of the automatic traveling vehicle is According to the distance from the autonomous vehicle, at least three types of areas are divided: a stop area, a deceleration area, and a prediction area. When the obstacle is present in the prediction area, the area is also divided into the deceleration area. It is determined whether or not the obstacle is present, and if the obstacle is also present in the deceleration area, the automatic vehicle is caused to travel at a reduced speed, and the obstacle is also present in the stop area. If it is determined that the automatic traveling vehicle is stopped, the automatic traveling vehicle is stopped.

According to a fourth aspect of the present invention, there is provided a control method of an automatic traveling vehicle having an obstacle detection sensor for detecting an obstacle present in front of the automatic traveling vehicle, wherein the area in front of the automatic traveling vehicle is According to the distance from the autonomous vehicle, the vehicle is divided into at least three types of areas, a stop area, a deceleration area, and a prediction area, and when it is determined that the obstacle is present in the prediction area, the deceleration area is determined. It is also characterized in that it is determined whether or not an obstacle exists, and if the obstacle does not exist in the deceleration area, the vehicle travels at a normal speed.

According to a fifth aspect of the present invention, the obstacle detection sensor includes:
It is an ultrasonic sensor.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A case where an embodiment of the present invention is applied to a battery-powered riding golf cart will be described below with reference to the drawings (FIG. 2).

1. Configuration of Battery-Type Riding Golf Cart The riding golf cart shown in FIG. 2 rotates the drive motor 4 by the battery 1 and rotates the rear wheels 6a, b via the transmission 5 to move forward or backward.

At the time of manual driving, the vehicle is operated by a steering handle 7 for steering the front wheels 6c and 6d, an accelerator pedal 8 for adjusting the vehicle speed, and a brake pedal 9 for braking the vehicle. Power supplied to the controller 2, the steering motor driver 11, the brake motor driver 13, and the like shown in FIG.

In this riding golf cart, an operation panel 24 is mounted in front of the driver's seat. The operation panel 24 has an automatic / manual mode selection switch 27, a start switch, a stop switch, a forward switch, a reverse switch, a display section for displaying any failure when it is detected, and a buzzer for sounding an alarm (not shown). Is installed.

The speed of the vehicle is detected by a vehicle speed sensor 20 mounted on the transmission 5, and the vehicle speed sensor
From 20, a pulse voltage corresponding to the speed is output to the controller 2. The controller 2 controls the vehicle speed by PID control using a feedback method.

On the other hand, the vehicle is braked by an electromagnetic clutch brake.
15. Three types of brakes were used: drum brakes 10a to 10d, and regenerative braking by the drive motor 4. When the golf cart is running, the electromagnetic clutch brake 15 attached to the rotation shaft of the drive motor 4 is energized to release the braking of the electromagnetic clutch brake 15.

2. Automatic driving A guide line 41 (FIG. 3) is buried in advance in a cart running path of a golf course capable of automatic driving.
By passing an alternating current of 1500 Hz, an alternating magnetic field is formed in the vicinity. In this riding golf cart, a T-shaped arm 34 that moves horizontally and substantially horizontally is provided at the front end of the vehicle, and guidance sensors 16a and 16b are disposed at two places of the arm 34, and their signals are transmitted to a controller. Output to 2.

Each of the induction sensors 16a and 16b uses a coil, detects an electromotive force generated in the induction sensor by the AC magnetic field, determines the position of the induction line, and moves the riding golf cart on the cart running path. Is guided along.

The controller 2 performs processing based on signals from the induction sensors 16a and 16b, and outputs a drive current corresponding to a steering instruction signal via a steering motor driver 11 to the steering motor 12a.
Send to Then, after the rotation speed of the steering motor 12 is reduced through the steering gear unit 19, the steering shaft 35 is rotated. By rotating the steering shaft 35, the front wheels 6c and 6d are steered via the steering mechanism 25 to control the traveling so that the vehicle does not deviate from the guidance line.

It should be noted that the steering wheel during automatic driving
7 is in a state of being separated from the steering shaft 35 and fixed by the steering gear unit 19, and its manual operation is disabled. Further, in order to detect the presence or absence of a failure of the steering motor 12, the drive current thereof is output to the controller 2 and is constantly monitored.

The magnet sensor 17 uses a coil and is mounted at a predetermined position of the vehicle so as to face the ground. On the other hand, a plurality of permanent magnets are embedded in a golf course at predetermined intervals with the N pole or the S pole facing the ground. When the vehicle equipped with the magnet sensor 17 passes above the plurality of embedded permanent magnets, the magnet sensor
An induced electromotive force is generated at 17. And the magnet sensor 17
By detecting the magnetic pole array pattern of each of the permanent magnets, travel control such as changing or stopping the speed of the vehicle is performed.

The vehicle is also provided with an inclination sensor 18, which outputs the gradient of the road on which the vehicle is traveling to the controller 2. The controller 2 makes a judgment with a sign of zero for a flat ground, a sign of plus for an uphill, and a sign of minus for a downhill, and calculates a larger value as the inclination gradient is larger, and activates each braking device described later.

When the golf cart stops, regenerative braking is applied to the drive motor 4, and at the same time, hydraulic drum brakes 10a to 10d attached to the front and rear wheels 6a to 6d are operated. The drum brakes 10a to 10d adjust the pressure in the hydraulic cylinder 22 by the rotation of the brake motor 14, and
It brakes 6d. When the speed detected by the vehicle speed sensor 20 that detects the rotation of the drive motor 4 becomes zero by braking the golf cart, the controller
From 2, the current flowing through the electromagnetic clutch brake 15 is cut off, the electromagnetic clutch brake 15 is closed, and the rear wheels 6a and 6b are locked.

When a player or the like passes in front of the vehicle body during automatic driving, the obstacle is detected by the obstacle detection sensor 36, and the vehicle body is braked via the controller 2. Note that an obstacle detection method using the obstacle detection sensor 36 according to the present invention will be described in detail in an embodiment described later.

3. Manual Operation This battery-powered riding golf cart can also be manually driven by ordinary manual operation. In this case, the automatic / manual mode selection switch 27 on the operation panel 24 is switched to the manual traveling mode. In this state, after the steering gear unit 19 releases the connection between the steering mechanism 25 and the steering motor 12, the steering mechanism 25 and the steering handle 7 are connected. Therefore, in this state, manual steering can be performed by operating the steering handle 7 by the driver.

During manual driving, the driver operates the accelerator pedal.
By stepping on 8, the electromagnetic clutch brake 15 is released to accelerate the vehicle body. Then, the driver sets the accelerator pedal 8
The regenerative braking is applied to the vehicle body when the foot is released.

Further, when the driver depresses the brake pedal 9, the vehicle body can be braked by the vehicle body drum brakes 10a to 10d. When the controller 2 confirms that the accelerator pedal has not been depressed and that the vehicle speed detected by the vehicle speed sensor 20 is zero, the current flowing through the electromagnetic clutch brake 15 is cut off, and the electromagnetic clutch brake 15 is closed. The wheels 6a and 6b are locked.

[0030]

1 is a flowchart showing an obstacle detection method according to the present invention, and FIG. 2 is a block diagram showing a configuration of a battery-powered riding golf cart. FIG. 3 is a schematic diagram of a running golf cart.

1. Overview of Obstacle Detection Method According to the Present Invention In the present invention, as the obstacle detection sensor 36, an ultrasonic sensor that causes few malfunctions even when mounted on a vehicle is used. As the obstacle detection sensor 36 used in the present invention, an integrated transmission / reception ultrasonic sensor having a transmission unit and a reception unit is used. From the transmission unit of the ultrasonic sensor, a signal having a pulse width of 1 ms is transmitted at a period of 31.8 ms toward the traveling direction. The transmitted ultrasonic wave is reflected when hitting an obstacle, and the reflected wave is detected by the receiving unit and output to the controller 2. The controller 2 outputs a stop command signal or a deceleration command signal to the drive motor driver 3 to control the golf cart to stop or decelerate.

As described above, the distance between the golf cart and the obstacle can be measured by the time from when the ultrasonic wave is transmitted until it is reflected. As shown in FIG. 3, in the following embodiment, L1 is set at a position at a maximum of 5.5 m in front of the golf cart 40 as an obstacle detection range. Then, L2 was set at a position of 3.5 m in the forward direction, and L3 was set at a position of 1.8 m in the forward direction.

Then, the range of L1 to L2 is set to the prediction area 46.
The range from L2 to L3 was defined as a deceleration area 45, and the range closer to the golf cart than L3 was defined as a stop area 44. As described later, when an obstacle is detected in the stop area 44, the golf cart 40 is controlled to stop, and when an obstacle is detected in the deceleration area 45, the golf cart decelerates. After the obstacle is detected in the predicted area 46 and the obstacle is further detected in the deceleration area 45, the golf cart is controlled to run at a reduced speed.

2. Detailed contents of the obstacle detection method according to the present invention The detailed contents of the obstacle detection method according to the present invention will be described with reference to the flowchart of FIG.

(1) Step 1 (S1) At first, the vehicle travels at the normal speed already instructed by the magnet or the like buried in the ground and proceeds to S2.

(2) Step 2 (S2) As the detection range of the obstacle detection sensor 36, L3 (1.8
m) and proceed to S3.

(3) Step 3 (S3) In S3, it is determined whether there is an obstacle in the range of L3. When an obstacle is detected in the range of L3 (stop area 44), the process goes to S13 (stop command) to stop the golf cart. On the other hand, if no obstacle is detected in the range of L3, the process proceeds to S4.

(4) Step 4 (S4) In S4, L2 is set as the detection range of the obstacle detection sensor 36.
(3.5 m), and then proceeds to S5.

(5) Step 5 (S5) In S5, the area within the range of L2 (the deceleration area or the stop area 4
In 4), it is determined whether there is an obstacle. If an obstacle is detected within this range, the process proceeds to S10, and if no obstacle is detected, the process proceeds to S6.

(6) Step 6 (S6) In S6, L1 is set as the detection range of the obstacle detection sensor 36.
(5.5 m), and then proceeds to S7.

(7) Step 7 (S7) It is determined whether there is an obstacle in the range of L1 (the prediction area 46, the deceleration area 45, or the stop area 44). If an obstacle is detected within this range, the flow goes to S8, and if no obstacle is detected, the flow returns to the first S1.

(8) Step 8 (S8) At S8, L2 is set as the detection range of the obstacle detection sensor 36.
(3.5 m) and the process proceeds to S9.

(9) Step 9 (S9) In S9, the area within L2 (the deceleration area 45 or the stop area
In step 44), determine whether there is an obstacle. If an obstacle is detected within this range, the procedure goes to S10, and if no obstacle is detected, the procedure returns to S1.

(10) Step 10 (S10) In S10, a deceleration command is issued to the golf cart, and S11 is executed.
Proceed to.

(11) Step 11 (S11) In S11, L3 is set as the detection range of the obstacle detection sensor 36.
(1.8 m) and the process proceeds to S12.

(12) Step 12 (S12) In S12, it is determined whether there is an obstacle in the range of L3. When an obstacle is detected in the range of L3 (stop area 44), the process goes to S13 (stop command) to stop the golf cart. On the other hand, if no obstacle is detected in the range of L3, the process returns to S8. This is because an obstacle may be detected in a short time in the future.

3. Features of the present invention As described above, the present invention has the following features.

A) When it is determined that an obstacle exists in the stop area In this case, the golf cart is stopped to prevent danger (S3, S12, S13). Therefore, the golf cart can be reliably prevented from colliding.

B) When it is determined that an obstacle is present in the deceleration area (S5, S9) In this case, after the golf cart has been decelerated and traveled (S10), it is determined that there is also an obstacle in the stop area. If it is determined (S12), the golf cart is stopped (S13). Therefore, the golf cart can be reliably prevented from colliding.

On the other hand, when it is determined that the obstacle exists in the deceleration area (S9), and when it is determined that the obstacle does not exist in the stop area (S12), the golf cart travels with the golf cart decelerated as it is. This is because an obstacle may be detected in a short time in the future. Then, when it is determined that the obstacle does not exist in the deceleration area (S9), the process returns to the first step and travels at a normal speed (S1).

Therefore, if there is a fixed obstacle such as a standing tree, and it is determined that there is no obstacle to the running of the golf cart, the vehicle passes by in a decelerated state.
You can run at normal speed again.

C) When it is determined that the obstacle is present in the predicted area (S7) In this case, it is determined whether or not the obstacle is also present in the deceleration area (S9), and the obstacle is also present in the deceleration area. If it is determined that the golf cart is present (S9), the golf cart is run at a reduced speed (S10). If it is determined that the golf cart is also present in the stop area (S12), the golf cart is stopped (S1).
3).

On the other hand, when it is determined that an obstacle is present in the prediction area (S7), and thereafter, it is determined that no obstacle is present in the deceleration area (S9), the process returns to the first step and returns to the normal step. (S1). Therefore, when the golfer or the like crosses the traveling path in front of the golf cart in a state without danger, it is determined that there is no obstacle to the traveling of the golf cart, and the golf cart can travel at a normal speed.

[0054]

As described above, by using the method of the present invention, the reliability of the obstacle detection sensor installed for the purpose of preventing the collision of the self-driving vehicle can be improved. It is a thing.

[Brief description of the drawings]

FIG. 1 is a flowchart of an obstacle detection method according to the present invention.

FIG. 2 is a block diagram showing the configuration of a battery-powered riding golf cart.

FIG. 3 is a schematic view of a golf cart during traveling.

[Explanation of symbols]

1: battery, 2: controller, 3: drive motor driver, 4: drive motor, 5: transmission, 6a,
b: rear wheel, 6c, d: front wheel, 7: steering handle, 8: accelerator pedal, 9: brake pedal, 10a
To d: drum brake, 11: steering motor driver, 1
2: Steering motor, 13: Brake motor driver, 1
4: brake motor, 15: electromagnetic clutch brake, 1
6a, b: inductive sensor, 17: magnet sensor, 18:
Inclination sensor, 19: steering gear unit, 20:
Vehicle speed sensor, 21: gear, 22: hydraulic cylinder, 23:
Brake motor driver switch, 24: operation panel,
25: steering mechanism, 27: automatic / manual mode selection switch, 34: arm, 35: steering shaft, 36: obstacle detection sensor, 40: golf cart, 41: guide wire, 4
2: fixed obstacle, 43: indefinite obstacle, 44: stop area, 45: deceleration area, 46: prediction area

 ──────────────────────────────────────────────────続 き Continued on the front page F-term (reference) 2G005 AA04 5H115 PA08 PC06 PG07 PI16 PU01 QE12 QN05 QN06 TB01 TD03 UB07 UB20 5H301 AA03 BB13 CC05 EE05 EE06 GG10 JJ01 LL02 LL03 LL07 LL08 LL14 5J083 AC02 AF02

Claims (5)

[Claims] 1. An automatic vehicle control system including an obstacle detection sensor for detecting an obstacle present in front of an automatic vehicle, wherein an area in front of the automatic vehicle is separated from the automatic vehicle by Is divided into at least three types of areas: a stop area, a deceleration area, and a prediction area in accordance with the distance of the vehicle. When the obstacle is present in the stop area, the automatic traveling vehicle is stopped. A control method for an autonomous vehicle. 2. An automatic traveling vehicle control system including an obstacle detection sensor for detecting an obstacle present in front of the automatic traveling vehicle, wherein a region in front of the automatic traveling vehicle is located at a distance from the automatic traveling vehicle. Is divided into at least three types of areas: a stop area, a deceleration area, and a prediction area. When the obstacle is present in the deceleration area, the automatic traveling vehicle is decelerated and travels. Stopping the self-driving vehicle when the obstacle is present in the stop area, and running the self-driving vehicle at a normal speed when the obstacle is not present in the deceleration area. A control method for an autonomous vehicle. 3. A control system for an automatic traveling vehicle having an obstacle detection sensor for detecting an obstacle present in front of the automatic traveling vehicle, wherein an area in front of the automatic traveling vehicle is separated from the automatic traveling vehicle by According to the distance, at least three areas of a stop area, a deceleration area, and a prediction area are divided in this order. When the obstacle is present in the prediction area, the obstacle is also present in the deceleration area. Determine whether there is, if the obstacle is also present in the deceleration area, decelerate the autonomous vehicle to travel,
An automatic traveling vehicle control method, wherein the automatic traveling vehicle is stopped when it is determined that the obstacle is also present in the stop area. 4. An autonomous vehicle control system including an obstacle detection sensor for detecting an obstacle present in front of the autonomous vehicle, wherein an area in front of the autonomous vehicle is located at a distance from the autonomous vehicle. Are divided into at least three types of areas, a stop area, a deceleration area, and a prediction area, and if it is determined that the obstacle is present in the prediction area, the obstacle is also included in the deceleration area. It is determined whether or not there is a vehicle, and if an obstacle does not exist in the deceleration area, the vehicle travels at a normal speed. 5. The control system for an automatic traveling vehicle according to claim 1, wherein said obstacle detection sensor is an ultrasonic sensor.