JP2009116860A - Vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a vehicle capable of performing proper travel control corresponding to a detected object with a simple configuration. <P>SOLUTION: A golf cart 10 traveling on a cart road CR has: object sensors 31 and 32 for transmitting an ultrasonic wave ahead, detecting that there is an obstacle ahead by receiving an ultrasonic wave reflected when it collides with the obstacle, and detecting the size of the obstacle; and a controller 25 for controlling the travel of the golf cart 10 in accordance with the size of the obstacle on the basis of the existence/absence of the detection of the obstacle by the object sensors 31 and 32 or when the object sensors 31 and 31 detect the obstacle. The object sensors 31 and 32 have regulation members 31a and 32a for regulating the width of a detection range by the ultrasonic wave transmitted from the object sensors 31 and 32 so as to be slightly wider than the width of the golf cart 10. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a vehicle provided with an object sensor for preventing a collision with a predetermined object when traveling on a predetermined course.

2. Description of the Related Art Conventionally, a vehicle that automatically travels on a certain course such as a golf cart has a collision prevention sensor (for example, see Patent Document 1). An object sensor comprising a pair of left and right ultrasonic sensors is provided at the front portion of the automatic traveling vehicle. Further, the automatic traveling vehicle is provided with an ultrasonic sensor located on one side and an ultrasonic sensor located on the other side. The vehicle is stopped when the distance at which the ultrasonic sensor located on the one side detects an obstacle determined by the time from transmission to reception is shorter than the set danger distance 1. Furthermore, the vehicle is stopped when the distance for detecting the obstacle determined by the time from the transmission to reception by the ultrasonic sensor located on the other side becomes shorter than the set danger distance 2. At that time, it has a control means for setting the distance so that the set danger distance 2 is shorter than the set danger distance 1. The vehicle is also provided with a control mechanism for changing the direction of the ultrasonic sensor in the turning direction.
Japanese Patent No. 2944814

  However, the conventional vehicle that automatically travels as described above requires a mechanism for controlling the direction of the ultrasonic sensor, which complicates the structure and increases the cost. In addition, by changing the set dangerous distance of the ultrasonic sensor located on one side, the detection distance when there is an obstacle near the outside of the curve of the traveling path is shortened, and deceleration or stop after detecting the obstacle May be delayed. Furthermore, no matter what the object to be detected by the ultrasonic sensor is, the same control causes the automatic traveling vehicle to decelerate or stop, so even if deceleration or stop is not necessary, unnecessary deceleration or stop is performed. It will happen.

  The present invention has been made to cope with the above-described problems, and an object of the present invention is to provide a vehicle capable of performing appropriate traveling control according to an object detected with a simple configuration.

  In order to achieve the above-mentioned object, a structural feature of the vehicle according to claim 1 of the present invention is a vehicle that travels on a predetermined course, and continuously transmits a transmission wave that is an ultrasonic wave or an electromagnetic wave for a predetermined time. An object sensor that receives a reflected wave that is an ultrasonic wave or an electromagnetic wave that is reflected when the object collides with the object, and the object is at least small in accordance with the time at which the object sensor receives the reflected wave. An object specifying device for classifying an object, a medium object, or a large object and a travel control device for controlling the travel of the vehicle corresponding to the classification of the object are provided.

  This object specifying device utilizes the fact that the size classification of the object can be specified by the time difference between the reflected wave with the shortest distance and the reflected wave with the longest distance from the object that the vehicle approaches. This makes it possible to travel on a predetermined course at a normal speed or at a lower speed depending on the size of an object that the vehicle approaches. In addition, the vehicle according to the present invention detects whether or not there is a predetermined object in front of the vehicle by transmitting the transmitted wave with an object sensor and receiving the reflected wave reflected from the object. . At the same time, if there is an object, the size of the reflected wave can be detected based on the continuous reception time. When the object sensor detects an object, the traveling control device controls the traveling of the vehicle according to the size of the object.

  According to a second aspect of the vehicle of the present invention, the travel control device causes the vehicle to travel at a speed lower than a normal travel speed on the course when the object classification is a middle object. That is.

  In the present invention, when an ultrasonic wave or electromagnetic wave received by the object sensor is continuously received, the object is classified into at least a small object, a medium object, or a large object, and the object classification is a medium object. The vehicle is made to run at a lower speed than the normal speed. As the small object in this case, for example, grass, garbage, or the like that does not cause trouble in traveling of the vehicle. And as a middle object, a rear collision, such as a person and other vehicles located ahead, must be avoided. Further, as a large object, a building, a wall, or the like is located outside the detection range of the object sensor by moving from the front position of the vehicle when the vehicle turns. Therefore, when the object is a middle object, it is determined that the object is an obstacle, and the vehicle can approach the middle object while traveling at a low speed. Further, the object classification may be increased to three or more by further classifying the small objects into extremely small objects such as grass and garbage and using the poles and trees as small objects.

  A configuration feature of the vehicle according to claim 3 of the present invention is that the travel control device has a time from when the object sensor transmits to when it receives the reflected wave is shorter than a predetermined value. And stopping the vehicle.

  In the present invention, the traveling control device is controlled to stop the vehicle when the time from the transmission of the ultrasonic wave or electromagnetic wave to the reception of the object sensor in the vehicle traveling at a low speed becomes shorter than the set value. According to this, the vehicle stops when the distance between the vehicle and the object approaching is shortened to the extent that attention is required, so that the vehicle can be prevented from colliding with the object. The set value is a preset value, and when it can be determined that the distance between the vehicle and the object is close enough to require attention, the time until the target sensor receives the reflected wave at the distance between the vehicle and the object. Set based on. Further, the set value may be a distance value obtained from the speed of the vehicle and the time until the reflected wave is received. In this case, the traveling control device stops the vehicle when the distance obtained by the reception time of the reflected wave becomes shorter than the set distance value.

  Further, in the configuration feature of the vehicle according to claim 4 of the present invention, the traveling control device causes the vehicle to travel at a normal speed when the classification of the object is a small object or a large object, The vehicle is stopped when the time until the reflected wave is received becomes a value shorter than the predetermined value.

  In the present invention, the traveling control device causes the vehicle to travel at a normal speed when the classification of the object is a small object or a large object, and sets the time from transmission of ultrasonic waves or electromagnetic waves to reception thereof (for example, The vehicle is to be stopped when the time becomes shorter than a value shorter than a value (for example, L1 in 1 millisecond). A value L1 shorter than the set value L2 in this case is such that when it can be determined that the distance between the vehicle and the object is so close that there is a possibility of collision with the object if the vehicle maintains the running state. Is set based on the time until the object sensor receives the reflected wave. Further, the value L1 may be a distance value obtained from the speed of the vehicle and the time until the reflected wave is received. In this case, the traveling control device stops the vehicle when the distance obtained by the reception time of the reflected wave becomes shorter than the installed distance value L1.

  According to this, when the object detected by the object sensor is a large object or a small object, the vehicle travels at a normal speed, but when the vehicle approaches the object for a short distance determined by the value L1, the travel control device Can stop the vehicle from colliding with an object. Note that the value L1 obtained from the distance between the vehicle and the object is a preset value, and the distance between the vehicle and the object is so close that there is a possibility of collision with the object if the vehicle maintains the running state. Set based on the distance that can be determined.

  Further, when the object is a small object, the traveling control device regards the object as not being an obstacle and causes the vehicle to travel at a normal speed, so that it is not necessary to slow down or stop the vehicle. When the object is a large object, the large object is originally installed near a predetermined course on which the vehicle travels and is judged not to be an obstacle for the time being, so that the vehicle travels at a normal speed. . In addition, when the object is a middle object, the vehicle travels at a low speed as described above, but if the middle object is out of the detection range of the object sensor, control is performed to return the traveling speed of the vehicle to the normal traveling speed. Done.

  Further, the structural feature of the vehicle according to claim 5 of the present invention is that the vehicle travels on a predetermined course, and transmits the transmitted wave continuously for a predetermined time and reflects when it collides with an object. An object sensor for receiving the reflected wave and a traveling control device for controlling the traveling of the vehicle when the object sensor provided on both sides of the front part of the vehicle receives the reflected wave. The travel control device includes a time from when one object sensor provided on both sides transmits to the time when the reflected wave is received, and when the other object sensor transmits the reflected wave. When the difference from the time until the time is received is shorter than a predetermined time, the vehicle is driven at a lower speed than the normal driving speed on the course.

  According to this, it is possible to appropriately prevent the vehicle from colliding with a person or an object on the course. For example, when there is a person on the course on which the vehicle travels, when the vehicle travels on the course, the object sensor located on the right side of the course receives the reflected wave when the object is detected. The difference between the time and the detection distance when the object sensor located on the left side of the course detects the object becomes short. In this case, since there is a person on the course of the vehicle, the traveling control device causes the vehicle to travel at a speed lower than the normal traveling speed. In other words, when the difference between the time and distance detected by both object sensors is shorter than a predetermined length, a person or object is located near the front of the vehicle, so that the object is determined to be an obstacle and the vehicle Decelerate. This can prevent the vehicle from suddenly approaching a person on the course.

  According to a sixth aspect of the present invention, there is provided a structural feature of a vehicle that travels on a predetermined course, transmits the transmitted wave continuously for a predetermined time, and reflects it when it collides with an object. An object sensor for receiving the reflected wave and a traveling control device for controlling the traveling of the vehicle when the object sensor provided on both sides of the front part of the vehicle receives the reflected wave. The travel control device includes a time from when one object sensor provided on both sides transmits to the time when the reflected wave is received, and when the other object sensor transmits the reflected wave. When the difference from the time until the time of receiving is longer than a predetermined time and the steering angle of the vehicle is smaller than a predetermined range centering on the steering angle when going straight, the vehicle is Lower than normal driving speed It is to travel to.

  According to this, the rear-end collision prevention when the vehicle turns can be appropriately performed. If there is a difference of a predetermined length or more between the time or distance detected by one object sensor and the time or distance detected by the other object sensor, and the vehicle has a small steering angle, the vehicle There is a risk of collision with an object if the vehicle continues to run. Therefore, the vehicle is decelerated by determining that the object is an obstacle. Since the vehicle does not face the front of the object, the difference in detection time and distance between the one object sensor and the other object sensor becomes longer, but the vehicle is traveling toward the object, Drive at low speed to prevent the danger of colliding with objects.

  As a predetermined range of the steering angle in this case, for example, when the steering angle when the vehicle goes straight is set to “0”, the left turn side is minus and the right turn side is plus, −10 degrees to +10 Between degrees. For this reason, the case where the steering angle of the vehicle is smaller than the predetermined range means that the steering angle is smaller than −10 degrees and larger than +10 degrees, and the absolute value is smaller than 10 degrees.

  According to a seventh aspect of the present invention, the travel control device includes a time until the reflected wave of the one object sensor is received and the reflection of the other object sensor. The vehicle is stopped when an average time with the time until the wave is received becomes shorter than a predetermined value.

  As a result, when the vehicle continues to travel straight at a lower speed than the normal speed toward the object, the vehicle approaches the object to a distance where it collides with the object when the vehicle travels straight ahead. Stop. As a result, the vehicle can be prevented from colliding with an object in advance. In addition, the predetermined value is determined based on the distance between the vehicle and the object when it can be determined that the distance between the vehicle and the object is close enough that the vehicle may collide with the object if the vehicle is kept running. It sets based on the time until the object sensor receives the reflected wave. The predetermined value may be the value L1. Further, the predetermined value may be a distance value obtained from the speed of the vehicle and the time until the reflected wave is received. In this case, the travel control device has a distance obtained by the average time of the reflected wave received by one object sensor and the reflected wave received by the other object sensor is shorter than the predetermined distance at which it is installed. If the vehicle stops.

  According to the eighth aspect of the present invention, the travel control device includes a time until the reflected wave of the one object sensor is received and the reflection of the other object sensor. When the difference from the time until the wave is received is a predetermined length or more and the steering angle of the vehicle is larger than the predetermined range, the vehicle is driven at a normal speed.

  Thus, when the vehicle is traveling with the steering angle being increased to avoid the object, the vehicle has no danger of colliding with the object, so the travel control device causes the vehicle to travel at a normal speed. For example, when a wall is provided along a course along which the vehicle travels, the time detected when the object sensor located inside the curve detects the wall when the vehicle travels on a curve The detected time (or distance) when the object sensor located outside the curve detects the wall is shorter than (or distance).

  Therefore, when there is a difference of a predetermined length or more in the difference between the time (or distance) detected by one object sensor and the time (or distance) detected by the other object sensor, When the steering angle is large, that is, when the steering angle of the vehicle is out of the predetermined range and is large to the left and right, it is considered that there is no obstacle and the vehicle is run as it is. The case where the steering angle of the vehicle is larger than a predetermined range is when the steering angle is smaller than −10 degrees or larger than +10 degrees, and when the absolute value is larger than 10 degrees.

  In addition, the structural feature of the vehicle according to claim 9 of the present invention is that the object sensor adds a width of a range of transmission by ultrasonic waves or electromagnetic waves to a width of about 20 cm to the left and right of the width of the vehicle. This is to provide a regulating member for regulating the width. In the present invention, the object sensor is a restricting member for restricting the width of the range transmitted by the ultrasonic wave or electromagnetic wave transmitted from the object sensor to a width of 20 cm to the left and right that is slightly larger than the width of the vehicle. It is in providing. According to this, the object sensor does not detect an object in a part greatly deviating from the part where the vehicle travels on the course as an obstacle, and an appropriate obstacle detection and vehicle traveling control can be performed.

  In addition, a structural feature of the vehicle according to claim 10 of the present invention is that the regulating member has a shape in which the diameter of the front portion is larger than that of the rear portion. With respect to the regulating member, the front side is larger in diameter than the rear side, so that the width of the range of the transmitted wave of the object sensor can be set to 20 cm when the size of the expanded diameter is appropriately set. it can.

  A feature of the vehicle according to claim 11 of the present invention is that the vehicle is a golf cart. The vehicle according to the present invention can be a variety of vehicles that travel on a course provided in a predetermined site, but is a vehicle that travels on a cart path of a certain distance in a golf course, such as a golf cart. Is particularly suitable. According to this, it is possible to reliably prevent collision with other golf carts and objects, and it is possible to obtain a golf cart in which traveling time is not prolonged by slowing down or stopping wastefully.

  Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings. 1 and 2 show a golf cart 10 as a vehicle according to the present invention. The golf cart 10 includes two front wheels FL and FR provided on the left and right sides of the front portion at the lower portion of the vehicle body 11 and two rear wheels RL and RR provided on the left and right sides of the rear portion of the lower portion of the vehicle body 11. And. Further, a front seat 12a for two people and a rear seat 12b for three people are provided side by side before and after the central portion of the vehicle body 11, respectively. Furthermore, a handle 13 is provided on the front side of the front seat 12 a in the front portion of the vehicle body 11.

  Further, a roof portion 14 is provided on the upper portion of the vehicle body 11 via support frames 14 a provided at four corners of the vehicle body 11. A bumper 15 a is attached to the lower part of the front end of the vehicle body 11, and a bumper 15 b is attached to the lower part of the rear end of the cowl 11 a constituting the rear part of the vehicle body 11. This golf cart 10 can be operated automatically or manually. In the case of manual driving, the driver sitting on the front seat 12a rotates the handle 13 to change the direction of the front wheels FL and FR to the left and right, and the golf cart 10 turns left. Or change the direction of travel while turning right.

  The handle 13 is fixed to the upper end of a steering shaft 13 a that extends from the front lower portion of the vehicle body 11 to the upper part of the rear portion and is rotatably installed around the shaft. And the lower end of the steering shaft 13a which supports the handle | steering-wheel 13 is meshing | engaged with the rack bar 16 installed in the horizontal direction. The rack bar 16 is configured to move left and right (in the axial direction of the rack bar 16) by the rotation of the steering shaft 13a, and the movement of the rack bar 16 changes the direction of the left and right front wheels FL and FR. The steering shaft 13a is composed of a lower side portion and an upper side portion, and a steering clutch 17 for connecting and disconnecting the lower side portion and the upper side portion is provided therebetween.

  When the steering clutch 17 connects the upper part and the lower part of the steering shaft 13a, the front wheels FL and FR are steered according to the operation of the handle 13 by the driver. When the upper side portion of the steering shaft 13a is separated from the lower side portion by the steering clutch 17, the handle 13 is fixed and stops at a fixed position. In this case, automatic operation is performed, and the lower part of the steering shaft 13a is rotated by the operation of the steering motor 18 provided in the lower part of the steering shaft 13a, and the front wheels FL and FR are turned in accordance with the rotation. Change to left or right. A steering angle sensor 18a for detecting the rotation angle of the steering shaft 13a is installed in the vicinity of the steering shaft 13a, and the steering motor 18 is controlled in consideration of the detection value of the steering angle sensor 18a.

  An accelerator pedal 21 and a brake pedal 22 are provided side by side below the handle 13 on the front side of the vehicle body 11. Further, on the rear side of the vehicle body 11, a drive motor 23 and a transmission 24 for transmitting the driving force of the drive motor 23 to the rear wheels RL and RR are provided. The accelerator pedal 21 and the brake pedal 22 are operated by the driver when the golf cart 10 is run. The accelerator pedal 21 is connected to the controller 25 via an accelerator potentiometer 21a. When the driver depresses the accelerator pedal 21, the position (depression amount) of the accelerator pedal 21 is detected by the accelerator potentiometer 21a.

  The detected value detected by the accelerator potentiometer 21a is transmitted to the controller 25 as an accelerator position signal. The controller 25 includes a travel control device 25a and an object identification device 25b according to the present invention, and further includes a CPU 29a, a ROM 29b, a RAM 29c, a timer 29d (see FIG. 5), and the like. Then, the controller 25 drives the drive motor 23 based on the accelerator position signal from the accelerator potentiometer 21 a and rotates the rear wheels RL and RR via the transmission 24. Thereby, the golf cart 10 travels while accelerating. When the golf cart 10 is automatically operated, the drive motor 23 is driven under the control of the controller 25 to rotate the rear wheels RL and RR.

  The brake pedal 22 is connected to a disc brake provided on each of the front wheels FL and FR and the rear wheels RL and RR via a disc brake system, and is connected to a controller 25 via a brake motor 22a. Yes. The brake pedal 22 is provided with a pressure sensor 22b for detecting the pressure generated when the brake pedal 22 is depressed.

  For this reason, when the driver steps on the brake pedal 22, the amount of depression of the brake pedal 22 is transmitted to the disc brakes provided on the front wheels FL and FR and the rear wheels RL and RR via the disc brake system. . Then, the rotational drive of the front wheels FL, FR and the rear wheels RL, RR is braked by the operation of the disc brake. Further, in the case of automatic driving, the brake motor 22a is driven by the control of the controller 25, so that the disc brake is operated and the front wheels FL, FR and the rear are operated in the same manner as when the driver steps on the brake pedal 22. The rotational drive of the wheels RL and RR is braked.

  The golf cart 10 includes a drive battery 26, a main relay 27, a control battery 26a, and an electromagnetic brake 28. The drive battery 26 supplies power for operating the drive motor 23 to the drive motor 23 via the main relay 27 and the controller 25. The main relay 27 connects or disconnects the drive battery 26 and the controller 25. The control battery 26 a supplies the controller 25 with power for operating the controller 25. The electromagnetic brake 28 is driven by the control of the controller 25 to actuate the disc brakes of the rear wheels RL and RR to lock the rear wheels RL and RR, thereby braking the golf cart 10.

  Further, the golf cart 10 includes a pair of object sensors 31, 32, a vehicle speed detection sensor 33, various types of sensors such as a guide line sensor 34 and a fixed point sensor 35, a remote control receiver 36, a warning buzzer 37, a power switch, a start / stop switch. (Not shown). The object sensors 31 and 32 are respectively attached to both sides of the front portion of the bumper 15a, and both include a transmission unit that transmits an ultrasonic wave and a reception unit that receives an ultrasonic wave reflected by the object. . The ultrasonic waves transmitted from the object sensors 31 and 32 are reflected from the object and returned to the object sensors 31 and 32 when the distance from the object located in front of the object sensors is within 6 m, for example. , 32 are set to the strength at which they can be received.

  Further, for example, a trumpet-shaped restricting member 31 a is attached to the front part of the object sensor 31, and a similar restricting member 32 a is attached to the front part of the object sensor 32. As shown in FIG. 3, the regulating members 31 a and 32 a regulate the width of the ultrasonic wave a transmitted from the object sensors 31 and 32 so as not to spread more than necessary. By the restriction members 31a and 32a, the width orthogonal to the traveling direction of the ultrasonic wave a transmitted from the object sensors 31 and 32 is a width obtained by adding about 20 cm to the left and right of the width of the golf cart 10 respectively. Is set to The restricting member has a shape in which the front side is larger in diameter than the rear side. With respect to the regulating member, the front side is larger in diameter than the rear side, so that the width of the range of the transmitted wave of the object sensor can be set to 20 cm when the size of the expanded diameter is appropriately set. it can. Further, when the width of the range of the transmitted wave is desired to be 10 cm, the size of the diameter expansion can be set to be appropriately smaller. The vehicle speed detection sensor 33 is installed at the rear part of the vehicle body 11 and detects the traveling speed of the golf cart 10.

  The guide wire sensor 34 has a bar-like member that extends forward from a connecting portion between the lower end portion of the steering shaft 13a and the rack bar 16 in a horizontally swingable manner, and a central portion that is connected to the front end portion of the bar-like member. It is attached to the attachment member of the support member 34a which consists of the attachment member extended right and left. In other words, the guide wire sensor 34 includes three sensors, and the three sensors are arranged on the mounting member of the support member 34a at right and left at regular intervals. The golf cart 10 travels on the cart path CR of the golf course while causing the guide line sensor 34 to follow the electromagnetic guide line GL shown in FIG.

  FIG. 4 shows a state in which the golf cart 10 is traveling on a cart road CR of a golf course, and the central portion in the width direction of the vicinity of the road surface in the basement of the cart road CR is along the traveling direction. The electromagnetic induction wire GL is provided. When the golf cart 10 automatically operates, the controller 25 controls the steering motor 18 to rotate the steering shaft 13a so that the guide wire sensor 34 follows the electromagnetic guide wire GL. In this case, the golf cart 10 travels so that the electromagnetic induction line GL is positioned inside the sensors on both sides of the guide line sensor 34.

  A fixed point member P that transmits a predetermined signal for automatically driving the golf cart 10 is provided in the vicinity of the electromagnetic induction line GL at a predetermined interval. The fixed point sensor 35 is provided on the bottom surface of the golf cart 10 and detects the fixed point member P provided on the cart path CR when the golf cart 10 travels. The golf cart 10 travels based on a travel instruction signal transmitted via the fixed point member P. The remote control receiver 36 is attached to the top of the golf cart 10 and receives the start signal and stop signal transmitted from the remote control 36 a and transmits them to the controller 25.

  The controller 25 starts control of each device based on the start signal sent from the remote control receiver 36 to automatically run the golf cart 10, and the golf cart 10 based on the stop signal sent from the remote control receiver 36. Stop running. As a result, the golf cart 10 can be started and stopped remotely by the remote controller 36a. When the warning buzzer 37 determines that the object detected by the object sensors 31 and 32 is an obstacle, or when the remaining amount of the drive battery 26 is low, an abnormality occurs in each device included in the golf cart 10. When the golf cart 10 travels, a warning sound is emitted under the control of the controller 25.

  The power switch is rotated between an ON position and an OFF position by inserting a key into a key hole provided in the vicinity of the handle 13 and rotating the key. By rotating to the ON position, the golf cart 10 It will be ready to run. Further, when the power switch is rotated to the off position, the golf cart 10 becomes unable to run. The start / stop switch is used when the golf cart 10 is automatically run, and is a switch for starting or stopping the golf cart 10. The operation state of the start / stop switch is transmitted to the controller 25 as a signal. When the manual start / stop switch is pressed while the power switch is in the ON position, the golf cart 10 starts to start, and when the manual start / stop switch is pressed again, the golf cart 10 stops.

  The ROM of the controller 25 stores programs and map data, which will be described later, and the RAM of the controller 25 stores various data in a rewritable state. The CPU of the controller 25 executes a program stored in the ROM based on various data. Further, as shown in FIG. 5, the controller 25 performs accelerator control for driving the motor, brake control for operating the brake, and steering control for steering the steering wheel. Sensor control is also performed to transmit and receive electromagnetic waves, and to process received signals based on transmitted and received waves. The controller 25 causes the object identification device 25b to recognize the classification of the object size based on the reception duration received from the sensor control. Then, the traveling control device 25a processes the classification of the object received from the object specifying device 25b to issue a deceleration instruction to the brake control, and decelerates and stops the golf cart.

  In this configuration, when an occupant rides the golf cart 10 to automatically drive the golf cart 10, first, the power switch and the start / stop switch are turned on. As a result, the drive motor 23 operates and the golf cart 10 starts running. The collision prevention control of the golf cart 10 in this case is performed according to the flowcharts shown in FIGS. This flowchart is repeatedly executed at predetermined time intervals by the CPU of the controller 25 after the power switch is turned on.

  The flowcharts shown in FIGS. 6 and 7 first start with the power switch turned on in step 100, and then proceed to step 102 to determine whether or not the golf cart 10 is running. Here, if the golf cart 10 does not start running and determines “No”, the processing of step 102 is repeated. This process is continued until the golf cart 10 starts traveling and the vehicle speed detection sensor 33 detects the traveling speed. When the golf cart 10 starts running and determines “Yes”, the process proceeds to step 104, where it is determined whether or not at least one of the object sensors 31 and 32 has detected an obstacle. If neither of the object sensors 31 and 32 has detected an obstacle, it is determined as “No” and the process proceeds to Step 106.

In step 106, it is determined whether or not the vehicle speed of the golf cart 10 is smaller than the traveling speed vkm / h. The traveling speed vkm / h is set in advance as a normal speed for traveling the golf cart 10 and is, for example, 8 km / h. Here, if the vehicle speed is lower than the traveling speed vkm / h, it is determined as “Yes” and the process proceeds to Step 108, where the process of accelerating the golf cart 10 with the acceleration α1 m / s ² is performed. Next, the process proceeds to step 102, and the above-described processing is repeated again. Then, processing for accelerating the golf cart 10 at an acceleration α1 m / s ² is performed until the vehicle speed of the golf cart 10 reaches the traveling speed vkm / h. When the vehicle speed of the golf cart 10 reaches the traveling speed vkm / h, Step 106 It is determined as “No” and the process returns to Step 102.

  The golf cart 10 travels at the traveling speed vkm / h until at least one of the object sensors 31 and 32 detects an obstacle. If at least one of the object sensors 31 and 32 detects an obstacle and determines “Yes” in step 104, the process proceeds to step 110. In this case, the obstacle sensors 31 and 32 detect the obstacle when the ultrasonic wave a transmitted from the object sensors 31 and 32 is reflected and returned after reaching the obstacle. Is performed by receiving. And the detection distance L is calculated | required by the time from transmission of the ultrasonic wave a to reception.

  The reflected wave of the ultrasonic wave a changes according to the front area of the obstacle (front area with respect to the traveling direction of the ultrasonic wave a), and the object sensors 31 and 32 transmit as shown in FIG. The reflected wave that returns after the ultrasonic wave a reaches the vehicle such as the golf cart 10a positioned in front is large, and the reflected wave that returns after reaching the pole 38 is small. Then, as shown in FIG. 9, the time until the ultrasonic wave a transmitted from the object sensors 31, 32 is reflected from the golf cart 10a or the pole 38 and received by the object sensors 31, 32 is T1, When the time during which the reflected wave is received by the object sensors 31 and 32 is T2, the reception duration of the reflected wave corresponding to the time T2 in the golf cart 10 shown in FIG. 10 is the pole 38 shown in FIG. Becomes longer than the reception duration of the reflected wave corresponding to time T2.

  FIG. 9 is a diagram showing a transmission wave and a reception wave of an ultrasonic wave a having a predetermined amplitude as time passes. The vertical axis direction in FIG. 9 indicates the voltage and corresponds to the loudness. The horizontal axis direction represents time, and the time d represents the time when the ultrasonic wave a is transmitted. Time e represents the time when the transmitted wave ends. Here, the time from time d to time e is the transmission duration time of the ultrasonic wave a. Time f represents the time when the first reflected wave arrives, and the time from time d to time f is T1. Time g represents the time when the last reflected wave arrives, and the time from time f to time g is T2.

  10 and 11 show the relationship between the magnitude of the detected wave (reflected wave) and the detection threshold value, respectively. The threshold value is a value that the ultrasonic wave a is not detected unless the received wave reaches a predetermined sound level. In FIGS. 10 and 11, the voltage on the vertical axis corresponds to the volume of sound, and the object sensors 31 and 32 cannot be recognized as a received wave unless they detect a predetermined voltage or higher. The reception continuation times b and c of the part equal to or greater than the threshold are set as the reception duration of the reflected wave. The size of the obstacle can be determined from the reception duration, and if the reception duration of the reflected wave is 3 ms to 4 ms, it is determined that the obstacle has a large front area such as the golf cart 10.

  Further, if the reception duration of the reflected wave is 1 ms to 2 ms, it is determined that the obstacle is a small front area such as the pole 38. For example, it is assumed that the reception duration time T2 of the object shown in FIG. 12A is 2 ms and has a small front area such as the pole 38. FIG. 12A shows the relationship between the golf cart 10 and the object at time d when the ultrasonic wave a is transmitted. The approach distance k1 represents the shortest distance between the golf cart 10 and the object, and the approach distance k2 represents the longest distance between the golf cart 10 and the object.

  At time d, a transmitted wave x is transmitted from the object sensors 31 and 32 of the golf cart 10. FIG. 12B shows the relationship between the golf cart 10 and the object 1 ms after the transmission of the ultrasonic wave a. The transmitted wave x represents the time when it collides with the object. The transmitted wave x collides with the location L of the object that is the shortest approach distance k1 between the golf cart 10 and the object. FIG. 12C shows the relationship between the golf cart 10 and the object 2 ms after the transmission of the ultrasonic wave a. The transmitted wave x collides with the point m of the object that is the longest approach distance k2 between the golf cart 10 and the object.

  FIG. 13A shows the relationship between the golf cart 10 and the object at time f 2 ms after the transmission of the ultrasonic wave a. The ultrasonic wave a colliding with the location L of the object becomes a received wave y1 and is reflected toward the golf cart 10. At time f, the received wave y1 reaches the golf cart 10 for the first time. That is, 2 ms after the transmission of the ultrasonic wave a is the time for the transmitted wave to reach the point L having the longest distance from the object, and the time for the first received wave y1 to reach the golf cart 10. Here, the time T1 from when the ultrasonic wave a is transmitted until the first received wave is detected is the time from the time d to the time f, which is 2 ms. The distance between the golf cart 10 and the object can be obtained from the time T1 by multiplying by 2 with the speed of sound. Here, the distance is the approach distance k1.

  FIG. 13B shows the relationship between the object and the golf cart 10 1 ms after the arrival of the received wave y1 at the golf cart 10 at a time 3 ms after the transmission of the ultrasonic wave a. The ultrasonic wave a that collides with the location m of the object that is the longest approach distance k2 between the golf cart 10 and the object is reflected to the golf cart 10 as a received wave y2. At this time, the received wave y2 has not reached the golf cart 10. FIG. 13B shows the relationship between the object and the golf cart 10 2 ms after the arrival of the received wave y1 after reaching the golf cart 10 at a time 4 ms after the transmission of the ultrasonic wave a. Time g is the last time the reflected wave y2 reaches the golf cart 10. Here, the time T2 between the time when the first received wave y1 of the ultrasonic wave a is detected and the time when the last received wave y2 is detected is changed from time f to time g, which is 2 ms.

  In order to obtain the size of the front of the object from time T2, the object identification device 25b has a correspondence between the distance based on time T1 and the size of the front of the object in advance. Here, only the size of the front surface of the object is considered, and the depth of the object is not considered. For example, when the approach distance k1 is 2 m and the time T2 is 2 ms, the traveling control device has an association that the size of the front surface of the object corresponds to a small object such as a pole. Even if the objects have the same front size, if the approach distance is 10 m, the time T2 may be 1 ms. The reception continuation time T2 changes according to the distance difference k3 obtained by subtracting the shortest approach distance k2 from the longest approach distance k2. The longer the distance difference k3, the longer the reception duration T2. In the present invention, the distance difference k3 simply represents the size of the object, and the distance difference k3 is obtained from the reception duration T2 of the ultrasonic wave a, so that the size of the object is conveniently determined. The golf cart 10 can be recognized before colliding with an object.

  Next, returning to the program, in step 110, a process of adopting the smaller value of the detection distances L of the object sensors 31, 32 is performed. This is because, when the object sensors 31 and 32 detect different objects, the object located closer to the object is more likely to be an obstacle than the object located far away. At the same time, when the object sensors 31 and 32 detect the same object, it is more appropriate to prevent the rear-end collision based on the object sensor 31 or the detection distance L of the object sensor 32 located closer to the object. It is because the process for can be performed. Here, when only one of the object sensors 31 and 32 detects an object as an obstacle, the detection distance L is adopted.

  Next, in step 112, when both of the object sensors 31 and 32 detect an obstacle, a process of calculating an average value of the magnitudes of both the obstacles as the magnitude m is performed. Thereby, the size m of the obstacle can be obtained with a smaller error. Also here, when only one of the object sensors 31 and 32 detects an obstacle, the detected size m is adopted.

  FIG. 14 shows a case where when one object sensor is provided at the front center of the golf cart 10, the size of the object (medium) is detected by ultrasonic waves from one angle by the object sensor. . Here, the right side surface of the object (middle) faces the front of the front part of the golf cart 10, and the ultrasonic wave n transmitted from the front center of the golf cart 10 collides with the object (middle). Suppose you are. For this reason, the reception duration T2 of the object sensor determined according to the difference between the longest contact distance s2 and the shortest approach distance s1 is, for example, 1 ms, and the size of the object (medium) is erroneously recognized as being small. Resulting in.

  On the other hand, FIG. 15 shows a case where the size of the object (medium) is detected by the ultrasonic wave a from two angles by the object sensors 31 and 32 provided on both sides of the front portion of the golf cart 10. . In this case, the transmission wave o and the transmission wave p of the ultrasonic wave a transmitted from both sides of the front portion of the golf cart 10 collide with the front surface and the back surface of the object (medium). For this reason, the reception duration T2 of the object sensors 31 and 32 determined according to the difference between the longest contact distance Q2 and the shortest approach distance Q1 is, for example, 4 ms, depending on the difference between the longest contact distance Z2 and the shortest approach distance Z1. The reception continuation time T2 of the object sensors 31, 32 determined in this way is, for example, 2 ms. According to this, the object sensors 31 and 32 obtain the average time of the reception duration T2 of each of the transmission wave o and the transmission wave p, and recognize that the reception duration T2 of the object (medium) is 3 ms. Can do. Therefore, by applying the ultrasonic wave a from two angles to the object (medium), the size of the object (medium) can be correctly recognized as being medium.

  Next, the program proceeds to step 114, where it is determined whether or not the detected size m is greater than m1 and less than or equal to m2. The size m is classified according to the type of obstacle assumed in advance as shown in Table 1 below.

  As shown in Table 1, when the obstacle is a small object such as grass, the size m is greater than m1 and less than m2, and when the obstacle is a person, The size m is assumed to be larger than m2 and smaller than m3. In the case where the obstacle is a car such as a golf cart 10 positioned in front, the size m is larger than m3 and less than or equal to m4, and when the obstacle is a building such as a wall. The size m is larger than m4.

  In this case, for example, the reception duration of the reflected wave of the object having the size m1 is 1 ms, the reception duration of the reflected wave of the object of the size m2 is 2 ms, and the reception duration of the reflected wave of the object having the size m3. Is 3 ms, and the reception duration time of the reflected wave of the object of size m 4 is 4 ms. This makes it possible to easily determine the type of object. An object whose size m is larger than m1 and smaller than m2 constitutes a small object according to the present invention, and an object whose size m is larger than m2 and smaller than m4 according to the present invention. An object that constitutes a middle object and whose size m is larger than m4 constitutes a large object according to the present invention. Further, as described above, the reception duration time of the reflected wave according to the classification of the object changes according to the distance between the golf cart 10 and the obstacle. The correspondence data between the approach distance and the reception continuation time is stored in the map data of the ROM 29b in the controller.

  For example, FIG. 16 illustrates a case where the controller 25 of the golf cart 10 recognizes a standing person as a middle object. The reception duration T2 corresponding to the difference k5 between the longest approach distance k4 and the shortest approach distance k1 is, for example, 4 ms. FIG. 17 shows a case where a person who is sitting is recognized as a middle object by the travel control device of the golf cart 10. The reception duration T2 corresponding to the difference k6 between the longest approach distance k5 and the shortest approach distance k1 is, for example, 3 ms. The reception duration time for detecting the person in FIG. 16 by the object sensors 31 and 32 is 4 ms, and the reception duration time for detecting the person in FIG. 17 by the object sensors 31 and 32 is 3 ms. 25 will recognize.

  FIG. 18 shows a case where the controller 25 of the golf cart 10 recognizes the building as a large object. The reception duration T2 corresponding to the difference k8 between the longest approach distance k7 and the shortest approach distance k1 is, for example, 10 ms. In this case, since the reception duration time during which the object sensors 31 and 32 detect the building of FIG. 18 is 10 ms, the controller 25 recognizes that the building is a large object.

  In step 114, if the detected obstacle is grass or the like and the size m is larger than m 1 and less than m 2, it is determined as “Yes”, and the traveling speed of the golf cart 10 is kept as it is. The process proceeds to step 116 while maintaining (traveling speed vkm / h or lower speed). If it is determined that the detected size m is larger than m2 and "No", the process proceeds to step 118, and it is determined whether or not the detected size m is larger than m4. If the detected obstacle is a wall or the like and the size m is determined to be “Yes” larger than m 4, the process proceeds to step 116 while maintaining the traveling speed of the golf cart 10 as it is.

  That is, here, as shown in FIG. 19, it is determined whether or not an obstacle detected according to the size m is regarded as an obstacle. If the size m is smaller than m1, detection by the object sensors 31 and 32 is impossible. If the size m is larger than m1 and less than or equal to m2, it is regarded as not an obstacle, and the traveling speed of the golf cart 10 is maintained as it is. If the size m is greater than m2 and less than or equal to m4, it is determined as an obstacle and the processing described later is performed. Further, if the size m is larger than m4, it is once regarded as not an obstacle, and the traveling speed of the golf cart 10 is maintained as it is.

  In step 116, it is determined whether or not the detection distance L is smaller than L1. In this case, the distance L1 is set as an approach distance at which the possibility of a rear-end collision appears when the golf cart 10 travels toward an obstacle at the same speed. If the obstacle is a small object such as grass and the golf cart 10 approaches this approach distance L1, the golf cart 10 if the position of the obstacle is outside the detection range of the object sensors 31 and 32. The traveling speed is maintained at the same traveling speed, and the process proceeds to step 102. Further, when the obstacle is a large object and the golf cart 10 approaches the approach distance L1, if the object sensors 31 and 32 still detect the obstacle, the process proceeds to step 120. In step 120, the process which operates the electromagnetic brake 28 and stops the golf cart 10 is performed. The program then proceeds to step 102.

  Thus, while the object sensors 31 and 32 detect an obstacle and the size m is less than m2 or larger than m4, the speed of the golf cart 10 is set to the traveling speed vkm / h or a running speed close thereto is maintained. Then, when the distance between the golf cart 10 and the obstacle reaches the approach distance L1, the electromagnetic brake 28 is actuated to urgently stop the golf cart 10. On the other hand, if the obstacle detected by the object sensors 31 and 32 is a person or a vehicle and the size m is larger than m 2 and smaller than m 4, “No” is determined in step 118 and the process proceeds to step 122. . In step 122, it is determined that there is an obstacle, and in step 124, processing for sounding the warning buzzer 37 is performed. Thereby, it is possible for the occupant of the golf cart 10 and the surrounding people to know that there is a person or vehicle obstacle in front of the golf cart 10.

  Next, in step 126, control for decelerating the golf cart 10 is performed. Here, the vehicle speed is calculated using an equation that subtracts a predetermined numerical value from the traveling speed vkm / h, and the golf cart 10 is driven based on the calculated vehicle speed. This predetermined numerical value is obtained as a product of the difference between the maximum detection distance L0 and the detection distance L of the object sensors 31 and 32 and the conversion coefficient A, and a value obtained by subtracting this value from the traveling speed vkm / h is decelerated. Car speed. That is, if the difference between the maximum detection distance L0 and the detection distance L is “0”, the golf cart 10 is caused to travel at the traveling speed vkm / h. As the detection distance L becomes shorter than the maximum detection distance L0, that is, as the golf cart 10 approaches the obstacle, the vehicle speed of the golf cart 10 is made slower than the traveling speed vkm / h.

  In step 128, it is determined whether or not the detection distance L is smaller than L2. The distance L2 in this case is an approach distance that is slightly longer than the distance L1 in the case of the emergency stop described above. The reason why the distance L2 is an approach distance longer than the distance L1 is that the fear of the golf cart 10 approaching a person on the golf course or a person riding on the golf cart 10 is not adjusted. Therefore, when the travel control device recognizes a person or a target object of the golf cart 10, the travel control device sets the approach distance L <b> 2 longer than the approach distance L <b> 1 for emergency stop, so that the golf cart 10 Can be prevented from suddenly approaching a person.

  The distance L2 is the speed at which deceleration processing is performed in step 126, and is set as a distance at which there is a possibility that the golf cart 10 cannot maintain an interval with the obstacle when traveling toward the obstacle. . Here, if a person or a vehicle is located far from the golf cart 10 and the detection distance L is equal to or greater than L2, or is out of the detection range of the object sensors 31 and 32, the determination is “No”. Return to 102. If the detected distance L is smaller than L2, “Yes” is determined, and the process proceeds to step 130.

In step 130, a semi-emergency stop process for stopping the golf cart 10 while decelerating at a deceleration rate α2 m / s ² is performed. In this case, the deceleration rate α2 m / s ² is set to be slightly larger than the deceleration rate when the golf cart 10 is slowly decelerated during normal running. Thereby, the golf cart 10 can be stopped in a state where a certain distance is maintained with respect to a person or a vehicle. Then, the program returns to step 102 and the above-described processing is repeated.

  20 and 21 show a program for running control when the golf cart 10 runs along the corner portion of the cart road CR. This program is also repeatedly executed at predetermined time intervals by the CPU of the controller 25 after the power switch is turned on. The flowcharts shown in FIGS. 20 and 21 start with the power switch turned on in step 200, and then perform the processing in steps 202 to 212. Among these, the processing of steps 202 to 208 is the same as the processing of steps 102 to 108 of the above-described program, and the processing from when the golf cart 10 starts traveling until the vehicle speed reaches the traveling speed vkm / h. Done.

  Steps 210 and 212 are the same as steps 110 and 112. Here, after at least one of the object sensors 31 and 32 detects an obstacle, the detection distance L and the size of the obstacle are detected. A process for obtaining the length m is performed. Then, in step 214, it is determined whether or not the detected size m is larger than m1. If the detected magnitude m is less than or equal to m1, it means that the obstacle once detected cannot be detected, so the routine proceeds to step 206, where the vehicle speed becomes the running speed vkm / h. Processing to accelerate to is performed. On the other hand, if the detected size m is larger than m1, the routine proceeds to step 216, where it is determined whether or not the difference between the detection distances L of the object sensors 31, 32 is 50 cm or more.

  Here, if the difference between the detection distances L of the object sensors 31 and 32 is 50 cm or more, it is determined as “Yes”, and the process proceeds to Step 218. Whether the steering angle of the steering wheel 13 is 10 degrees or more or −10 degrees or less. Determine whether or not. Here, there is a case where the steering angle of the steering wheel 13 is small and is not more than 10 degrees or less than -10 degrees, that is, within a range of -10 degrees to 10 degrees. In this case, if the difference between the detection distances L of the object sensors 31 and 32 is small and not more than 50 cm in step 216, both are determined as “No” and the process proceeds to step 220. In this case, it is considered that the object sensors 31 and 32 have detected an obstacle. Further, when the difference between the detection distances L of the object sensors 31 and 32 is 50 cm or more and the steering angle of the steering wheel 13 is outside the range of −10 degrees to 10 degrees, and “Yes” is determined in step 218. Therefore, it is determined that the obstacle is not detected, and the process proceeds to step 202.

  That is, steps 216 to 220 are cases where the golf cart 10 travels in the corner portion of the electromagnetic induction wire GL shown in FIG. At that time, the golf cart 10 passes the corner portion by passing the position indicated by the reference numeral 10b from the position indicated by the reference numeral 10a and reaching the position indicated by the reference numeral 10c. The traveling control of the golf cart 10 at the position indicated by reference numeral 10b in such a case is shown. When the golf cart 10 approaches the obstacle that is the wall, if there is almost no difference in the detection distance L between the object sensors 31 and 32, the golf cart 10 goes straight toward the front of the obstacle. Therefore, it can be determined that there is an obstacle in the traveling direction. However, if there is a significant difference in the detection distance L between the object sensors 31 and 32, a corner like the golf cart 10 indicated by reference numeral 10b is used. It can be determined that the wall has been detected when passing through the portion.

  For this reason, it is further determined whether or not the golf cart 10 is turning based on the steering angle of the handle 13. If the golf cart 10 is turning, the golf cart 10 is not obstructed without colliding with the obstacle. Judge that it goes past the neighborhood. If the golf cart 10 is not turning, it is considered that there is an obstacle, and the routine proceeds to step 222. Thereafter, in steps 222 to 228, the same processing as that executed in steps 124 to 130 is performed. Thereby, the golf cart 10 can be made to run at a constant interval with respect to a person, a car, a building, or the like. Then, the program proceeds to step 202 and the above-described processing is repeated.

  As described above, the golf cart 10 according to the present embodiment includes the object sensors 31 and 32 that detect whether there is an obstacle ahead and also detect the size of the obstacle if there is an obstacle. When the object sensors 31 and 32 detect an obstacle, the controller 25 controls the travel of the golf cart 10 according to the size of the obstacle. For this reason, when the obstacle is small and it is not necessary to slow down or stop, the golf cart 10 is driven at a normal speed. In addition, when the obstacle is large and a rear-end collision must be avoided, the golf cart 10 is driven at a low speed, for example, 3 km / h. Furthermore, when the golf cart 10 that is traveling at a low speed approaches the obstacle within the approach distance L1, it is possible to perform traveling control according to the size of the obstacle such as emergency stop of the golf cart 10.

  In addition, since the two object sensors 31 and 32 are provided, the obstacle can be detected from two angles, so that the presence / absence of the obstacle and the size of the obstacle can be detected with higher accuracy. Furthermore, in the present invention, when there is a difference of a predetermined length or more in the detection distance L between the object sensors 31 and 32, if the steering angle of the handle 13 is large, it is considered that there is no obstacle and the golf cart 10 is run as it is. Even if the detection distance L of the object sensors 31 and 32 has a difference of a predetermined length or more, if the steering angle of the handle 13 is small, the golf cart 10 will collide with an obstacle as it continues to travel. There is a fear. In that case, the golf cart 10 is decelerated. For this reason, traveling control when the golf cart 10 turns can be appropriately performed.

  Further, in the golf cart 10 according to the present embodiment, the regulating member 31a for regulating the width of the detection range of the ultrasonic waves transmitted from the object sensors 31 and 32 to be slightly larger than the width of the golf cart 10. 32 a is provided for the object sensors 31 and 32. For this reason, the object sensors 31 and 32 do not detect an object in a portion greatly deviated from the portion where the golf cart 10 travels as an obstacle, and an appropriate obstacle can be detected.

  Further, the vehicle according to the present invention is not limited to the above-described embodiment, and can be implemented with appropriate modifications. For example, in the above-described embodiment, the object sensors 31 and 32 are sensors that transmit ultrasonic waves. However, light, infrared rays, electromagnetic waves having a short wavelength, or the like can be used instead of ultrasonic waves. In the above-described embodiment, the vehicle is the golf cart 10 or the like, but the vehicle is not limited to the golf cart, and may be various vehicles such as a four-wheeled vehicle and a motorcycle.

1 is a side view showing a golf cart according to an embodiment of the present invention. It is the block diagram which showed the outline of the golf cart. It is the top view which showed the detection range of the target object sensor. It is explanatory drawing which showed the state which a golf cart drive | works a cart road. It is explanatory drawing which showed the various control which a controller performs. It is the flowchart which showed steps 100-112 of the program for implementing rear-end collision prevention control. It is the flowchart which showed steps 114-130 of the program for implementing rear-end collision prevention control. It is explanatory drawing which showed the reflected wave according to the magnitude | size of an obstruction. It is the graph which showed time until an outgoing wave is reflected, and the width of a reflected wave. It is the graph which showed the reflected wave of a big obstacle. It is the graph which showed the reflected wave of a small obstacle. It is explanatory drawing which showed the state which an ultrasonic wave advances between a golf cart and a target object, (a) at the time of transmission of an ultrasonic wave, (b) after 1 ms, (c) shows the state after 2 ms. Yes. It is explanatory drawing which showed the state which an ultrasonic wave advances between a golf cart and a target object, (a) is 2 ms after transmission of an ultrasonic wave, (b) is 3 ms after, (c) is the state after 4 ms. Show. It is explanatory drawing which showed the state in which the object sensor detects an object, when one object sensor is provided in the front center of the golf cart. It is explanatory drawing which showed the state in which the object sensor detects an object when the object sensor is provided in the front both sides of the golf cart. It is explanatory drawing which showed the state which recognizes the person who stands as a middle object. It is explanatory drawing which showed the state which recognizes the person who sits down as a middle object. It is explanatory drawing which showed the state which recognizes a building as a large object. It is explanatory drawing which showed the reference | standard of whether it considers as an obstruction according to the magnitude | size of an obstruction. It is the flowchart which showed step 200-214 of the program for implementing rear-end collision prevention control at the time of a golf cart drive | working a corner part. It is the flowchart which showed step 216-228 of the program for implementing rear-end collision prevention control when a golf cart drive | works a corner part. It is explanatory drawing which showed the state which a golf cart drive | works a corner part.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 ... Golf cart, 25 ... Controller, 31, 32 ... Object sensor, 31a, 32a ... Restriction member, a ... Ultrasonic wave, CR ... Cart road.

Claims (11)

A vehicle traveling on a predetermined course,
An object sensor that continuously transmits a transmission wave that is an ultrasonic wave or an electromagnetic wave for a predetermined time and receives a reflected wave that is an ultrasonic wave or an electromagnetic wave that is reflected when it collides with an object;
An object identification device that classifies the object into at least a small object, a medium object, or a large object according to the time when the object sensor receives the reflected wave, and controls the traveling of the vehicle corresponding to the classification of the object A traveling control device to
A vehicle characterized by the provision of The vehicle according to claim 1, wherein the travel control device causes the vehicle to travel at a speed lower than a speed at which the vehicle travels normally on the course when the classification of the object is a middle object.   The vehicle according to claim 2, wherein the traveling control device stops the vehicle when a time from when the object sensor transmits to when the reflected wave is received becomes shorter than a predetermined value.   The traveling control device causes the vehicle to travel at a normal speed when the classification of the object is a small object or a large object, and the time until the reflected wave is received is shorter than the predetermined value. The vehicle according to claim 1, wherein the vehicle is stopped when it becomes. A vehicle traveling on a predetermined course,
An object sensor that continuously transmits the transmitted wave for a predetermined time and receives the reflected wave that is reflected when it collides with an object;
A travel control device that controls travel of the vehicle when the object sensors provided on both sides of the front part of the vehicle receive the reflected wave;
Is provided in the vehicle,
The travel control device receives a time from when one object sensor provided on both sides transmits to the time when the reflected wave is received, and receives the reflected wave from when the other object sensor transmits. A vehicle characterized in that the vehicle travels at a lower speed than a normal traveling speed on the course when the difference from the time until the time is shorter than a predetermined time. A vehicle traveling on a predetermined course,
An object sensor that continuously transmits the transmitted wave for a predetermined time and receives the received wave that is reflected when it collides with an object;
A travel control device that controls travel of the vehicle when the object sensors provided on both sides of the front part of the vehicle receive the reflected wave;
Is provided in the vehicle,
The travel control device receives a time from when one object sensor provided on both sides transmits to the time when the reflected wave is received, and receives the reflected wave from when the other object sensor transmits. If the difference from the time until the vehicle is longer than a predetermined time and the steering angle of the vehicle is smaller than a predetermined range centering on the steering angle when going straight, A vehicle that travels at a lower speed than the traveling speed.   The traveling control device has a predetermined time in which an average time between the time until the reflected wave of the one object sensor is received and the time until the reflected wave of the other object sensor is received is set. The vehicle according to claim 5 or 6, wherein the vehicle is stopped when shorter than a value.   The traveling control device has a difference between a time until the reflected wave of the one object sensor is received and a time until the reflected wave of the other object sensor is received over a predetermined length, The vehicle according to claim 6, wherein when the steering angle of the vehicle is larger than the predetermined range, the vehicle is driven at a normal speed.   9. The object sensor according to claim 1, further comprising a restricting member for restricting a width of a transmission range by the transmitted wave to a width obtained by adding a width of about 20 cm to the left and right of the width of the vehicle. The vehicle according to any one of the above.   The vehicle according to claim 9, wherein the restricting member has a shape in which the diameter of the front side is larger than that of the rear side.   The vehicle according to any one of claims 1 to 10, wherein the vehicle is a golf cart.

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