JPH06189610A - Automotive vehicle equipped with obstacle sensor - Google Patents

Abstract

PURPOSE:To prevent obstacle sensors installed in a mobile vehicle capable of performing the unmanned travel from discriminating a body located at a site not to be an obstacle as 'the presence of the obstacle' in turning the car body. CONSTITUTION:The direction of a pair of right and left ultrasonic sensors 23 and 24 installed in the front of a mobile car body 2 is changed and regulated so as to face nearly the turning direction according to the steering angle of the turning. The set dangerous distance in which a body is discriminated as an obstacle with the ultrasonic sensor located on the outside of the turning is simultaneously set so as to be shorter than that of the ultrasonic sensor provided on the inside of the turning.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention comprises a steering control device for enabling unmanned automatic traveling along a traveling route,
Further, the present invention relates to an autonomous vehicle that detects a distance to an obstacle by at least one of a pair of left and right obstacle sensors such as a pair of ultrasonic sensors mounted on a vehicle body and makes an emergency stop when the distance is less than a certain value. It is a thing.

[0002]

2. Description of the Related Art For example, the applicant of the present invention has previously described the utility model 2-70.
As disclosed in Japanese Patent No. 210, etc., in an unmanned work vehicle such as a chemical sprayer (speed sprayer) used in an orchard or the like, a magnetic field generated from an electromagnetic induction cable laid between tree rows in the orchard, An unmanned traveling vehicle is known, which is detected by a pair of left and right magnetic sensors mounted on a vehicle body and is steered and controlled substantially along the guide cable.

Further, for example, in Japanese Patent Laid-Open No. 60-234507, in an unmanned vehicle such as a chemical sprayer (speed sprayer) used in an orchard or the like, an ultrasonic sensor is mounted on the front of the vehicle body in a forward direction. Due to obstacles (objects)
It is disclosed that a distance up to is detected, and when this distance falls within the emergency stop setting range, it is determined that "there is an obstacle" and the vehicle body is stopped.

[0004]

By the way, when the traveling vehicle is controlled to turn to the next tree row at the end of the tree row, the steering angle of the wheels is in the turning direction, but the front of the vehicle body is It is generally facing outward from the traveling direction. In that case, if an ultrasonic sensor is provided in the front of the vehicle body so that the direction (direction of orientation) is fixed, the vehicle body attempting to turn around an object such as a fence located outside the turning will be Even if there is no risk of contact (collision), the distance from the ultrasonic sensor located outside the turning to the object is within the emergency stop setting range, and it is judged that there is an obstacle, and an emergency stop is performed. There was a problem of control.

The present invention aims to solve this problem.

[0006]

In order to achieve this object, a sensor for detecting a traveling route, a steering angle sensor,
In an automatic traveling vehicle comprising a control means for executing steering control based on the detection results of these sensors, the invention according to claim 1 is an obstacle such as a pair of left and right ultrasonic sensors provided in the front part of the vehicle body. The object sensor is configured to be rotatable left and right via the rotation drive means, and is provided with control means for determining an emergency stop based on distance data from at least one of the left and right obstacle sensors to the obstacle. On the other hand, there is provided control means for controlling the direction of the pair of obstacle sensors so as to substantially face the turning direction according to the magnitude of the steering angle and the turning direction. In the invention according to claim 2, an emergency stop is performed based on the distance data from at least one of the left and right sensors among obstacle sensors such as a pair of left and right ultrasonic sensors provided in the front part of the vehicle body. While setting the control means for determining, the set danger distance to the obstacle by the pair of obstacle sensors is set so that the obstacle sensor on the outside of the turn is shorter than that of the obstacle sensor on the inside of the turn. It is provided with a control means.

[0007]

According to the structure of the present invention, ultrasonic waves (infrared rays) are transmitted from a transmitter in an obstacle sensor such as an ultrasonic sensor or an infrared sensor mounted on a front portion of a vehicle body toward a target or an obstacle. ) Is irradiated, and the time to return to the receiver after being reflected from the target object or the like is measured, the distance to the target object can be detected. As a result, if it is determined that the vehicle that has entered the travel route is within a certain distance (within the set danger distance range) from the front of the vehicle body on the normal substantially straight travel route, an emergency stop is performed.

An object (object) existing at a position considerably close to the front part of the vehicle body during turning and the part outside the turning.
However, normally, there is no contact or collision between the object and the vehicle body. However, in the turning path, the direction of the vehicle body is often at least outside the tangent of the arc of the turning path, and in that case, the left and right sides of the vehicle body in front of the vehicle body in a direction substantially parallel to the longitudinal axis of the vehicle body. Of the pair of obstacle sensors, the distance from the obstacle sensor located on the outside of the turn to the target object will fall within the range of the set danger distance, and an emergency stop will occur due to an obstacle during a normal turn. To do.

Therefore, as in the invention described in claim 1,
When the orientations of the pair of left and right obstacle sensors are controlled so as to substantially face the turning direction in accordance with the turning direction and the steering angle thereof, the obstacle sensors located outside the turning do not interfere with the turning operation. As a result of being able to prevent the object at a location from being detected as an obstacle, it is possible to carry out a smooth turning operation without causing an unnecessary emergency stop.

According to the second aspect of the present invention, the set danger distance to the obstacle by the obstacle sensor located outside the turning is set to be shorter than that of the obstacle sensor inside the turning. In the same manner as described above, it is possible to prevent detection of an object at an outer side of the turning that does not interfere with the turning operation as an obstacle, and it is possible to perform a smooth turning work.

Further, in any of the above-mentioned inventions, since the obstacle sensor located inside the turning can detect the object located in the part from the inside of the turning, an emergency stop is performed if the distance to the sensor is within a predetermined danger distance. can do.

[0012]

EXAMPLES Next, an example in which the steering control device of the present invention is applied to an automatic traveling type chemical sprayer (speed sprayer) will be described.
It has a driving and operating section with a handle 3 at the front of the vehicle body 2,
A chemical liquid tank 4 is provided at the rear portion of the vehicle body 2 and a spray portion 5 is provided at the rear portion thereof.

The spray section 5 is composed of a large number of spray nozzles 6 which are provided on the outer peripheral surface of the vehicle body 2 excluding the lower surface thereof so as to be radially outward at appropriate intervals.
And a blower 5a that sends air outwardly of the radius is attached,
The spray nozzles 6 can be spray-controlled so as to perform spraying work in three sections on the left and right and the upper surface of the vehicle body 2, or in two sections on the left and right. Reference numerals 7 and 7 are left and right front wheels, and reference numerals 8 and 8 are left and right rear wheels. These four wheels are the engine 13
Is a so-called four-wheel drive type in which the power from the vehicle is transmitted through each of the traveling transmission mechanisms 14 and can be driven. Further, the front steering device 9 and the rear steering device 10 respectively turn the wheels in the left and right directions. It is a so-called four-wheel steering type that can change the rotation.

The front steering device 9 and the steering wheel 3 are connected via a steering mechanism which is well known in the art. This steering mechanism is a mechanism including a mechanical or hydraulic system.
The front steering device 9 can change the direction of the left and right front wheels 7, 7 by operating a double-acting hydraulic cylinder 15 attached to the steering mechanism. Similarly, also in the rear steering device 10, the direction of the left and right front wheels 8, 8 can be changed by operating a pair of left and right hydraulic cylinders 16 attached to the steering mechanism.

The hydraulic circuit 17 shown in FIG.
From the front wheel steering device 9 to the hydraulic cylinder 15 of the front steering device 9 and from the rear steering device 10 to the hydraulic cylinder 16 of the rear steering device 10 via the electromagnetic control valve 19. The steering angle sensor capable of detecting the steering angle of the steering wheel 7 and the reference numeral 22 denotes the steering angle sensor capable of detecting the steering angle of the rear wheel 8. In this case, the average value of the orientation angles of the left and right wheels may be obtained and detected.

Reference numerals 23 and 24 denote a pair of left and right ultrasonic sensors as obstacle sensors provided in the front part of the vehicle body 2. The transmitters 23a and 24a and the receivers 23b and 24b are connected to the step motor 25, respectively. 25, and is provided so as to swing and rotate on both left and right sides in the traveling direction of the work vehicle 1. Further, rotary encoders 26, 26 for detecting the directions of the step motors 25 or the ultrasonic sensors 23, 24 are provided in association with the step motors 25.

The object (obstacle) located on the left side in the traveling direction of the vehicle body 2 is mainly the ultrasonic sensor 23 on the left side.
Detected on the right side of the vehicle body 2 (obstacle)
Mainly shares the detection range so that the ultrasonic sensor 24 on the right side can detect. An infrared sensor may be used as the obstacle sensor. A pair of left and right magnetic sensors 27, 27 are provided on the lower surface side of the front portion of the vehicle body 2 or the like.
The magnetic sensors 27, 27 may be pickup coils formed by winding an electric conductor in a coil shape, or may be Hall elements, Hall ICs, magnetoresistive elements, or magnetic transistors. The strength of the magnetic field generated from the induction cable 28 embedded in the ground along the traveling path between the rows of the objects W such as trees connected to an AC current generator (not shown) is applied to the pair of magnetic sensors 27, 27. And the pair of left and right magnetic sensors 27, 2
The difference in distance from the central processing unit (CPU) 2 such as a microcomputer, which will be described later, is used to determine the lateral displacement deviation between the axis of the guide cable 28 and the center line of the vehicle body 2 and the lateral displacement direction.
Calculate with 9.

A central processing unit 29 in the control circuit block diagram of the embodiment shown in FIG. 4 includes a read-only memory (ROM) 30 in which a program for control described later is stored, and read / write at any time for temporarily storing various data. A possible memory (RAM) 31 and an input / output interface 32 are connected to the input / output interface 32. That is, the magnetic sensors 27, 27 and the steering angle sensor 2
1, 22 and rotary encoders 26, 26 and danger distance setters 33, 33 such as volumes connected to the wave receivers 23b, 24b of the ultrasonic sensors 23, 24, respectively.
And input each of these input signals to the central processing unit 29 via the input / output interface 32. In the danger distance setters 33 and 33, the ultrasonic sensors 23 and 24 are used.
If the distance from the object to the object W becomes a certain value or less, it is dangerous, and the operator or the like can change and set the magnitude of the distance for emergency stop of the vehicle body by brake operation, fuel supply cut, or the like. .

Further, a signal from the central processing unit 29 is sent to the step motor 25,
Drive circuits 34, 34 for 25, and each ultrasonic sensor 2
Predetermined signals are sent to the output control circuits 35, 35 of the wave transmitters 23a, 24a in 3, 24. By adjusting the output adjustment circuits 35, the maximum reach of the ultrasonic waves output by the ultrasonic sensors 23 and 24 can be adjusted.

Further, the input / output interface 32 is provided with drive circuits 36 and 37 such as electromagnetic solenoids for the electromagnetic control valves 19 and 20 of the steering hydraulic cylinders 15 and 16, a drive circuit 38 for operating the braking means, and fuel to the engine 14. The drive circuits 39 for the shut-off valves that cut off the supply are each connected. Next, in the central processing unit 29, control for directing the directions of the ultrasonic sensors 23, 24 to the turning direction and control for changing the set danger distance of the ultrasonic sensors located outside the turning at that time will be described.

As shown in FIG. 5, the pair of left and right magnetic sensors 27, 27 guides the guide cable 2 so that the vehicle body travels along the guide cable 28 arranged along the traveling route.
The strength of the magnetic field from 8 is detected, and the amount of lateral deviation of the center line of the vehicle body 2 with respect to the axis of the guide cable 28 and the lateral deviation direction thereof are calculated from the difference between the detected values. The steering control instruction amount of the vehicle body 2 is determined so as to be equal to or less than a predetermined allowable value, and the drive circuits 36 and 37 of the control valves 19 and 20 for the front and rear steering devices 9 and 10 are operated. If the steering control is performed in this manner, the work vehicle 1 can move along the tree row at the substantially central position of the row of the objects W (trees) on the left and right sides without lateral displacement. Then, the steering angles of the front wheels 7 and the rear wheels 8 that change their directions according to the steering control can be detected by the steering angle sensors 21 and 22.

It is considered that the steering angle on the straight traveling route is minute, and in that state, as shown in FIG.
A pair of left and right ultrasonic sensors 2 as the obstacle sensor
The step motors 25, 25 are driven so that the directions of 3, 24 are substantially parallel to the center line 2a of the vehicle body 2. The orientations of the ultrasonic sensors 23 and 24 are determined by the rotary encoder 2
It can be determined by the detection values of 6, 26.

As shown in FIG. 7, at the turning point,
The steering control instruction amount is determined so that the angle becomes larger than the steering angle on the straight travel route. The steering angle and steering direction (right or left) in that case are the steering angle sensor 2
If the steering angle is larger than the set value detected by the CPUs 1 and 22 and input to the central processing unit 29, the directions of the left and right ultrasonic sensors 23 and 24 with respect to the vehicle body 2a (angles θR and θ).
The step motors 25, 25 are driven so that L) becomes a predetermined value (the angle at which the front wheels 7 substantially move in the turning direction).
The (angle θR, θL) is the rotary encoder 26, 2
It can be read (detected) by the detection value of 6, and feedback control is performed. The left and right ultrasonic sensors 2
The directions of 3 and 24 (angles θR and θL) may be controlled so as to increase proportionally as the steering angle increases, or the left and right angles θR and θL are not the same, and θR> θL
You may set so that it becomes.

Further, at the turning point, as shown in FIG. 7, the ultrasonic sensor 23, which is an obstacle sensor located on the outside of the turning, sets a set danger distance SR at which it is judged that the obstacle W1 is present on the inside of the turning. The sound wave sensor 24 is set to be shorter than the set danger distance SL. In this case, the SR / SL ratio may be controlled to decrease in proportion to the increase in the steering angle. One example is
It shows in FIG. The horizontal axis indicates that the orientation of the ultrasonic sensors and the vehicle body axis are parallel when the inclination angle of each ultrasonic sensor 23, 24 with respect to the vehicle body axis is 0 °, and the vertical axis indicates the set danger distance.

In the embodiment shown in FIG. 7, the control of the direction of the obstacle sensor and the control of changing the set danger distance are simultaneously executed at the time of turning, but only the control of the direction of the obstacle sensor changes the set danger distance. It may be only change control. In this way, when the central processing unit 29 determines that the distance from the obstacle W1 to the ultrasonic sensor 23 or 24 and thus to the front end portion of the vehicle body 2 is within a predetermined set dangerous distance, the central processing unit 29 is mounted on the vehicle body 2 or remotely. An alarm device such as a buzzer provided on an operating device (not shown) is activated, and in addition to this, the brake drive means and / or the engine stop device is activated to stop the traveling vehicle 1 in an emergency.

The set danger distance may be changed by the danger distance setter 33, but for safety, the set value is stored in advance in a readable / writable memory (RAM) so that the operator cannot change it unintentionally. May be. The sensor for controlling the vehicle along the traveling route may be an ultrasonic sensor or an infrared sensor provided outward on both left and right side surfaces of the vehicle body 2. Further, it may be a type in which only the front or rear steering devices 9 and 10 are steered and controlled, or the front and rear wheels 7,
It is also possible to adopt a format in which 8 are changed so as to have the same orientation at the same time. Further, the change and adjustment of the rotation angle (orientation angle) of the obstacle sensor may be mechanically linked with the front steering device 9 by a link mechanism or the like.

[Brief description of drawings]

FIG. 1 is a plan view of a traveling vehicle.

FIG. 2 is a side view of the same.

FIG. 3 is a schematic explanatory diagram of a steering device.

FIG. 4 is a block diagram of a control device.

FIG. 5 is a plan view showing a positional relationship between an ultrasonic sensor and an object row.

FIG. 6 is an explanatory diagram showing the relationship between the orientation of the vehicle body and the orientation of the obstacle sensor when traveling straight.

FIG. 7 is an explanatory diagram showing the relationship between the orientation of the vehicle body and the orientation of the obstacle sensor during turning.

FIG. 8 is a diagram showing a relationship between an obstacle sensor and a set danger distance.

[Explanation of symbols]

 1 Traveling Vehicle 2 Vehicle Body 5 Spraying Part 7 Front Wheel 8 Rear Wheel 9 Front Steering Device 10 Rear Steering Device 21,22 Steering Angle Sensor 23,24 Ultrasonic Sensor 25 Step Motor 26 Rotary Encoder 27 Magnetic Sensor 28 Induction Cable 29 Central Processing Unit 36, 37, 38, 39 drive circuit

Claims (2)

[Claims] 1. An automatic traveling vehicle comprising a sensor for detecting a travel route, a steering angle sensor, and a control means for executing steering control based on the detection results of these sensors, the vehicle being provided at a front portion of a vehicle body. An obstacle sensor such as a pair of left and right ultrasonic sensors is configured to be rotatable leftward and rightward through a rotation driving means, and at least the distance data from one of the left and right obstacle sensors to the obstacle is used.
On the other hand, a control means for determining an emergency stop is provided, and a control means for controlling the direction of the pair of obstacle sensors so as to substantially face the turning direction in accordance with the magnitude of the steering angle and the turning direction. A self-driving vehicle with an obstacle sensor. 2. An automatic traveling vehicle comprising a sensor for detecting a travel route, a steering angle sensor, and a control means for executing steering control based on the detection results of these sensors. Of obstacle sensors such as a pair of left and right ultrasonic sensors, at least one of the left and right sensors is provided with control means for determining an emergency stop from the distance data to the obstacle, while the obstacle by the pair of obstacle sensors is provided. A vehicle equipped with an obstacle sensor is provided with a control means for setting a set danger distance to the obstacle sensor on the outside of the turn to be shorter than that of the obstacle sensor on the inside of the turn. .