JP2006110209A - Small electric vehicle equipped with travelling support device, and method for controlling the small electric vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a small electric vehicle equipped with a travelling support device for preventing a collision with an obstacle. <P>SOLUTION: When a measurement obstacle distance L (step S1) comes to be not more than a target stop distance (YES in a step S7), a control acceleration signal OFF flag is set to "1" (step S8). Till the establishment of an acceleration zero release condition (YES in a step S4), the control acceleration signal OFF flag is kept to be "1" and an acceleration opening is forcibly made to be zero (steps S8, S9). The driving of an electric motor 24 is forcibly stopped till the establishment of the acceleration zero release condition and the vehicle 1 is forcibly made to be a stop state. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a small electric vehicle including a driving support device and a control method for the small electric vehicle, and more particularly to a small electric vehicle including a driving support device used by a physically handicapped person or an elderly person and a control method for the small electric vehicle.

  2. Description of the Related Art Conventionally, there is a small electric vehicle that is used as a moving means by a disabled person or an elderly person who is difficult to walk. Unlike a general automobile, this small electric vehicle is regarded as a pedestrian under the Road Traffic Law and can travel on an outdoor sidewalk or indoors where pedestrians pass.

  The sidewalk where pedestrians pass is different from the roadway where vehicles such as automobiles pass in a certain direction, and the moving speed of pedestrians is extremely low and varies depending on each pedestrian. However, the direction is not limited to a certain direction, and differs depending on each pedestrian. For this reason, other pedestrians may suddenly appear on the sidewalk from the direction opposite to the traveling direction of the small electric vehicle.

  Therefore, a driver (occupant) of a small electric vehicle needs to travel while avoiding a collision with a pedestrian or the like on a sidewalk, and the conventional small electric vehicle has a problem that there is a large burden on driving of the occupant. It was.

In order to solve the above-described problem, an ultrasonic sensor is provided to stop the vehicle before the obstacle comes into contact with or collides with the vehicle, and based on the ultrasonic reception time of the ultrasonic sensor, Conventionally, there is a small electric vehicle that includes a travel support device that measures a distance and stops the vehicle when the measured distance is equal to or less than a predetermined distance (target stop distance) that is set in advance (for example, Patent Documents). 1).
Registered Utility Model No. 2603288

  However, in the above-described conventional small electric vehicle, the vehicle has not reached the target stop distance when the measured distance is not less than or equal to the target stop distance even though the vehicle has actually reached the target stop distance. In order to bring the vehicle closer to the target stop distance, the vehicle travel is started again, and as a result, the vehicle may collide with an obstacle. Such problems occur because the incident angle of the ultrasonic wave on the obstacle becomes oblique depending on the stationary state of the obstacle and an error occurs in the measurement distance, or the obstacle absorbs ultrasonic waves from clothes, etc. If the object is easy to be measured, the ultrasonic wave will be absorbed, resulting in an error in the measurement distance, or unlike a stationary object such as a wall, if the pedestrian is an obstacle, the measurement distance will fluctuate and become unstable. This is because the distance varies and the measured distance may not be less than the target stop distance even though the small electric vehicle is actually less than or equal to the target stop distance.

  The objective of this invention is providing the control method of a small electric vehicle provided with the driving assistance apparatus which can prevent the collision with an obstruction, and a small electric vehicle.

  In order to achieve the above object, a small electric vehicle including the driving support device according to claim 1 includes a handle having an accelerator lever and steering a front wheel, and a seat on which a passenger sits at the rear of the vehicle body behind the handle. A small electric vehicle comprising a battery mounted below the seating seat, an electric motor that drives rear wheels with electric power of the battery, and a travel support device that controls the electric motor, Is a distance measuring means for detecting an obstacle in front of the vehicle body and measuring a distance to the obstacle; an accelerator operation amount detecting means for detecting an operation amount of an accelerator lever; and the measured obstacle distance and Accelerator control means for outputting a control accelerator signal representing the control accelerator amount according to the detected accelerator operation amount, and based on the output control accelerator signal. Motor control means for controlling the output of the electric motor, and the accelerator control means determines that the accelerator is in an OFF state when the measured obstacle distance is equal to or less than a target stop distance, and the accelerator OFF state. A first control accelerator signal indicating that the accelerator operation amount is zero until a release condition is satisfied, and the motor control means stops the electric motor when receiving the first control accelerator signal; The accelerator OFF state release condition is at least one of the measured obstacle distance being greater than or equal to a target stop release distance greater than the target stop distance and the accelerator operation amount being 0. And

  A small electric vehicle according to a second aspect is characterized in that in the small electric vehicle according to the first aspect, the accelerator control means is detachable.

  The method for controlling a small electric vehicle according to claim 3 is mounted on a handle having an accelerator lever and steering a front wheel, a seat on which a passenger sits at the rear of the vehicle body behind the handle, and a lower portion of the seat. A method for controlling a small electric vehicle comprising a battery, an electric motor that drives a rear wheel with the electric power of the battery, and a driving support device that controls the electric motor, and detecting an obstacle ahead of the vehicle body A distance measuring step for measuring the distance to the obstacle, an accelerator operation amount detecting step for detecting the operation amount of the accelerator lever, and a control accelerator amount according to the measured obstacle distance and the detected accelerator operation amount A control accelerator signal output step for outputting a control accelerator signal indicating the output of the electric motor based on the output control accelerator signal. The control accelerator signal output step determines that the accelerator is in an OFF state when the measured obstacle distance is less than or equal to a target stop distance, and the accelerator OFF state release condition is satisfied. A first control accelerator signal indicating that the accelerator operation amount is 0 until the motor control step stops the electric motor when the first control accelerator signal is received, and the accelerator OFF state The release condition is characterized in that the measured obstacle distance is at least one of a target stop release distance larger than the target stop distance and the accelerator operation amount is zero.

  According to the present invention, when the measured obstacle distance is equal to or less than the target stop distance, the accelerator operation amount of the occupant is zero until the measured obstacle distance is equal to or greater than the target stop release distance that is greater than the target stop distance. Since the electric motor is forcibly stopped until at least one of the above times, if the small electric vehicle is located near the target stop distance, the small electric vehicle is stopped and the measured obstacle distance is accurate. Even if this is not the case, the small electric vehicle can be prevented from colliding with an obstacle.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 is a right side view of a small electric vehicle including a driving support apparatus according to an embodiment of the present invention, FIG. 2 is a plan view of the small electric vehicle of FIG. 1, and FIG. FIG. 4 is a front view of the small electric vehicle, and FIG. 4 is a rear view of the small electric vehicle of FIG. Hereinafter, the left and right and front and rear directions of the small electric vehicle are referred to based on the occupant.

  A small electric vehicle 1 (hereinafter referred to as “vehicle 1”) including a driving support apparatus according to an embodiment of the present invention includes a vehicle body frame 2 and a front end of the vehicle body frame 2 as shown in FIGS. A pair of front wheels 3 that can be steered left and right, which are respectively attached via suspensions (not shown) having suspensions on both the left and right sides of the body, and rear wheels (not shown) that have suspensions on the left and right sides of the rear end of the body frame 2 A pair of rear wheels 4 respectively attached via suspension parts, a seat support frame 5 formed at the rear part of the body frame 2, and a widthwise central portion of the front end of the body frame 2 And a steering shaft 6.

  The vehicle 1 also includes a seating seat 7 that is rotatably supported in a horizontal plane on an upper portion of the seat support frame 5, and a handle 8 that is attached to the upper end of the steering shaft 6. The occupant D can steer the front wheel 3 left and right via the steering shaft 6 by turning the handle 8 left and right.

  The body frame 2 is formed in a substantially platform shape, for example, a pair of left and right main pipes extending in the front-rear direction and a pair of main pipes connected by a plurality of cross members. The body frame 2 has a footrest plate 9 formed in the front portion thereof.

  The seat 7 is a single seat and includes a backrest 10 and a pair of left and right armrests 11 pivotally supported in a vertical plane (in the direction of the arrow in FIG. 1). In addition, the seating seat 7 can be fixed in a predetermined direction by an angle determination mechanism (not shown), so that passengers can get on and off.

  As shown in FIG. 2, a floor plate 12 made of, for example, a synthetic resin is placed on the footrest plate 9, whereby a low floor type footrest floor 13 is placed between the handle 8 and the seating seat 7. Is formed. In addition, a leg shield 14 that includes the steering shaft 6 is erected on the front end portion of the footrest plate 9. A rear body 15, which is a synthetic resin cover member covering the seat support frame 5, is formed behind the footrest plate 9 and below the seating seat 7.

  The leg shield 14 is configured by combining a front cover member 16 and a rear cover member 17 made of synthetic resin, and protects the legs of the occupant D in the front. A pair of left and right front fenders 18 projecting forward and covering the upper portions of the pair of front wheels 3 are formed at the lower part of the leg shield 14. The front surface of the front cover member 16 of the leg shield 14 has a front for loading cargo. A basket 19 is provided.

  Further, a distance measuring sensor 20 shown in FIG. 6 described later is attached to the front cover member 16 of the leg shield 14 below the seating surface of the seating seat 7 and above the front fender 18 (see FIG. 3). . The front upper portion of the vehicle 1 has a front end of the front basket 19 located in the forefront in a side view (FIG. 1), then a front end of the front fender 18, and then a front cover 16 of the leg shield 14. The distance measurement sensor 20 is located behind the front ends of the vehicle 1 as long as the measurement area does not interfere with the front basket 19 and the front fender 18.

  The distance measuring sensor 20 includes a distance measuring sensor 20a (long range sensor 20a) that is one long range sensor and distance measuring sensors 20b and 20c (short range sensors 20b and 20c) that are two short range sensors. The long range sensor 20a and the short range sensors 20b and 20c are arranged on a horizontal plane (see FIG. 3). Further, in the width direction of the leg shield 14, the long range sensor 20a is disposed in the center and the short range sensors 20b and 20c are disposed on the left and right, respectively. The distance measuring sensor 20 detects an obstacle in front of the vehicle 1 in a wide range. And it is comprised so that the distance to the target object can be measured.

  As described above, since the distance measuring sensor 20 is attached to the front cover member 16 of the leg shield 14 below the seating surface of the seating seat 7, it also detects an obstacle that is out of sight of the occupant D. Can do. The distance measuring sensor 20 is disposed behind the front basket 19 and the front fender 18 in the vehicle 1 and is protected by the front basket 19 and the front fender 18 even when the vehicle 1 collides with an obstacle. The In this way, the vehicle 1 is configured to prevent the failure of the distance measurement sensor 20 due to a collision.

  Further, a headlamp 21 is disposed at the lower front portion of the leg shield 14, below the front basket 19 and directly above the front fender 18, and at the center in the width direction of the leg shield 14. In addition, a pair of front turn signal lamps 22 are disposed on the left and right sides of the headlight 21 at the lower front portion of the leg shield 14. Since the front turn signal lamp 22 is formed in a substantially L shape that goes around from the front surface of the leg shield 14 to the left and right side surfaces, the front turn signal lamp 22 is visible from the front and side of the vehicle 1.

  As shown in FIGS. 1 and 2, inside the rear body 15, a power unit 23 having an electric motor 24, a pair of left and right power supply batteries 25, a control unit 26 in FIG. And devices such as a battery charger (not shown) are provided. The power unit 23 transmits the driving force of the electric motor 24 to the rear wheel 4. As shown in FIG. 4, a pair of rear turn signal lamps 27 are disposed at the left and right corners of the rear end of the rear body 15, and the rear turn signal lamps 27 are also the same as the front turn signal lamps 22. The rear body 15 is formed in a substantially L shape that wraps around the left and right side surfaces from the rear surface.

  FIG. 5 is a perspective view of the handle 8 of the vehicle 1.

  As shown in FIG. 5, the handle 8 includes a base portion 31, a pair of substantially U-shaped grips 32 attached to the left and right side surfaces of the base portion 31, and an accelerator lever 33 attached to the right side surface of the base portion 31. A brake lever 34 attached to the left side of the base 31, a pair of left and right rearview mirrors 35 attached to the upper surface of the base 31, and a control panel 36 formed on the upper surface of the base 31. The grip 32 is of a so-called tiller handle type.

  The occupant D can control the output of the electric motor 24 by operating the accelerator lever 33, and can thereby control the output of the electric motor 24 of the vehicle 1. The occupant D can brake the vehicle 1 by operating the brake lever 34.

  The control panel 36 includes a maximum speed adjustment switch 37 that can adjust the maximum speed of the vehicle 1 to an arbitrary speed, and a traveling direction switch 38 that can switch the traveling direction of the vehicle 1 between forward and reverse. And a driving support control ON / OFF switch 39 that can select whether or not to execute a driving support process described later with reference to FIG. As these switches 37 to 39, for example, dial switches are used so that the occupant D can operate the switches easily and accurately. The maximum speed adjustment switch 37 can set the maximum speed within a range of, for example, 7 km / h or less.

  The handle 8 includes a turn signal lamp switch 40 for operating the front turn signal lamp 22 and the rear turn signal lamp 27 on the rear surface of the base 31 on the left and right sides, and an alarm switch 41 for operating an alarm device (not shown). And a main switch 42 for operating the vehicle 1.

  FIG. 6 is a block diagram illustrating a schematic configuration of the control unit 26 of the vehicle 1.

  As shown in FIG. 6, the control unit 26 is connected to the main controller (motor control means) 51 that controls each part of the vehicle 1, and is connected to the main controller 51, so that the driving support process of FIG. 7 described later can be executed. A collision prevention controller (accelerator control means) 52, an accelerator lever operation amount detection sensor 53 for detecting the amount of operation of the accelerator lever 33 by the occupant D, a vehicle speed sensor 54 for detecting the vehicle speed of the vehicle 1, and an obstacle ahead of the vehicle 1 A distance measuring sensor 20 for detecting an object and measuring a distance from the vehicle 1 to the obstacle, and a driving support control ON / OFF switch 39 of FIG. 5 are provided.

  Further, the control unit 26 includes a maximum speed setting switch 37 and a traveling direction changeover switch 38 shown in FIG. The distance measurement sensor 20, the maximum speed setting switch 37, the traveling direction changeover switch 38, the driving support control ON / OFF switch 39, the main switch 42, the accelerator lever operation amount detection sensor 53, and the vehicle speed sensor 54 are connected via a collision prevention controller 52. It is connected to the main controller 51. The main controller 51 is connected to the electric motor 24.

  Each of the distance measuring sensors 20a, 20b, and 20c as the distance measuring sensor 20 includes an ultrasonic transmission unit and an ultrasonic reception unit. As will be described later with reference to FIG. The distance from the vehicle 1 to the obstacle can be calculated based on the elapsed time from when the transmitted ultrasonic wave is reflected by the obstacle and then received by the ultrasonic wave receiving unit.

  Further, each of the collision prevention controller 52 and the main controller 51 is a box-shaped unit, and in the vehicle 1, the distance measurement sensor 20, the maximum speed setting switch 37, the traveling direction changeover switch 38, and the travel support control ON / OFF switch 39. The main switch 42, the accelerator lever operation amount detection sensor 53, the vehicle speed sensor 54, and the collision prevention controller 52 are detachably connected via a connector. The collision prevention controller 52 is also connected to the main controller 51. And is detachably connected. Accordingly, the collision prevention controller 52 is removed from the control unit 26 and the main controller 51 is connected to the switches 37 to 39 and 42 and the sensors 20, 53, and 54, so that the travel support device according to the present embodiment is provided. There can be no conventional vehicle.

  Accordingly, the connector for connecting the conventional main controller of the vehicle and each sensor and each switch is removed, and the collision prevention controller 52 in this embodiment is attached between the main controller and each sensor and each switch via the connector. Thus, it is possible to configure a travel support apparatus according to the present embodiment which will be described later.

  Next, a driving support process executed by the driving support device included in the vehicle 1 will be described.

  In the present embodiment, the control unit 26 of FIG. 6 constitutes a travel support device.

  FIG. 7 is a flowchart of a driving support process executed by the driving support device.

  This process is executed by the collision prevention controller 52 when the driving support control ON / OFF switch 39 is in the ON state. When the travel support control ON / OFF switch 39 is in the OFF state, the main controller 51 outputs the electric motor 24 based on the operation amount of the accelerator lever 33 of the occupant D detected by the accelerator lever operation amount detection sensor 53. And the vehicle speed of the vehicle 1 is controlled within the range of the maximum speed set by the maximum speed setting switch 37. Further, this process is executed at regular intervals, for example, every 100 ms.

  When the driving support control ON / OFF switch 39 is in the ON state, first, the distance from the vehicle 1 to the obstacle is measured (step S1). In step S1, the obstacle distance is measured every 100 ms, for example.

  The measurement of the distance to the obstacle in step S1 is performed as follows. As shown in FIG. 8, the time (transmission time) T1 when the ultrasonic wave is transmitted from the ultrasonic wave transmission unit of the distance measurement sensor 20, and the transmitted ultrasonic wave is received by the ultrasonic wave reception unit after being reflected by the obstacle. Time (reception time) T2 is detected by the distance measuring sensor 20, and a process time T from transmission to reception of ultrasonic waves is calculated from the detected transmission time T1 and reception time T2 (T = T2-T1). . Next, the ultrasonic process distance La is calculated by multiplying the calculated process time T by the ultrasonic propagation velocity (sound velocity Va) (La = Va × T), and the calculated process distance La is ½. The obstacle distance L, which is the distance from the vehicle 1 to the obstacle, can be calculated (L = La × 1/2).

  As described above, in this travel support device, the distance measurement sensor 20 is disposed on the left and right sides of the one long range sensor 20a disposed at the center in the width direction of the vehicle 1 and the long range sensor 20a. Since it is composed of the short range sensors 20b and 20c, it is possible to detect obstacles in a wide range even when using highly directional ultrasonic waves, and measure the obstacle distance L for a wide range of obstacles. And the reliability of the measured obstacle distance L can be improved. This is because obstacles located in the vicinity of the vehicle 1 that cannot be accurately detected by the long range sensor 20a that transmits strong ultrasonic waves can be accurately detected by the short range sensors 20b and 20c.

  Next, after measuring the obstacle distance L in step S1, an accelerator lever operation amount signal representing the amount of accelerator lever that is the operation amount of the accelerator lever 33 of the occupant D is received from the accelerator lever operation amount detection sensor 53 (step S2). ), It is determined whether or not the control accelerator signal OFF flag is “1” (step S3). The control accelerator signal OFF flag represents information requesting that the vehicle 1 be stopped by stopping the driving of the electric motor 24 regardless of the operation amount of the accelerator lever 33 of the occupant D by “1”. Is a flag that represents information requesting to control the output of the electric motor 24 and control the vehicle speed of the vehicle 1 based on the control accelerator amount described later.

  If the control accelerator signal OFF flag is “1” as a result of the determination in step S3, whether or not the accelerator lever amount is 0 based on the accelerator lever operation amount signal received in step S2, or in step S1 It is determined whether or not the measured obstacle distance L is greater than or equal to a preset target stop release distance (step S4). The target stop cancellation distance is set to 1 m, for example. On the other hand, if the result of determination in step S3 is that the control accelerator signal OFF flag is “0”, the process proceeds to step S6 described later.

  As a result of the determination in step S4, when the accelerator lever amount is 0, or when the measured obstacle distance L is equal to or larger than the preset target stop release distance, the control accelerator signal OFF flag is switched to “0” ( Step S5). On the other hand, as a result of the determination in step S4, if the accelerator lever amount is not 0, or if the measured obstacle distance L is not equal to or greater than the target stop release distance, the process proceeds to step S8 described later.

  After performing the process of step S5 or when the control accelerator signal OFF flag is “0” as a result of the determination in step S3, the control accelerator amount is calculated according to the measured obstacle distance L and the vehicle speed V in step S1. (Step S6). This control accelerator amount is a value corresponding to the accelerator lever amount in step S2, and the main controller 51 controls the output of the electric motor 24 based on this control accelerator amount. The control accelerator amount in step S6 is calculated based on the measured obstacle distance and the current vehicle speed V from, for example, a preset equation or map that represents the relationship between the measured obstacle distance and vehicle speed and the control accelerator amount. The control accelerator amount is a value set so that the vehicle 1 can stop at an interval of the target stop distance with respect to the obstacle. Therefore, as the distance between the vehicle 1 and the obstacle approaches the target stop distance, the control accelerator amount decreases, the output of the electric motor 24 decreases, and the vehicle speed decreases.

  Next, it is determined whether or not the measured obstacle distance L is equal to or less than a preset target stop distance (step S7). The target stop distance is set to 20 cm, for example. If the measured obstacle distance L is not less than or equal to the target stop distance as a result of the determination in step S7, the process proceeds to step S10 described later. On the other hand, if the measured obstacle distance L is less than or equal to the target stop distance as a result of determination in step S7, or if the accelerator lever amount is not 0 as a result of determination in step S4, or the measured obstacle distance L is not greater than or equal to the target stop release distance. In this case, the control accelerator signal OFF flag is switched to “1” (step S8), and the control accelerator amount calculated in step S6 is changed to 0 (step S9).

  Next, after the process of step S9 or when the measured obstacle distance L is not less than or equal to the target stop distance as a result of the determination in step S7, the control accelerator amount calculated in step S6 or set to 0 in step S9, and step The accelerator lever amount detected in S2 is compared to determine whether or not the control accelerator amount is larger than the accelerator lever amount (step S10). If the result of determination in step S10 is that the control accelerator amount is greater than the accelerator lever amount, the control accelerator amount is changed to the accelerator lever amount (step S11). On the other hand, if the control accelerator amount is not larger than the accelerator lever amount as a result of the determination in step S10, the process proceeds to step S12 described later.

  Next, after the process of step S11 or if the result of determination in step S10 is that the control accelerator amount is not larger than the accelerator lever amount, a control accelerator signal indicating the control accelerator amount is output to the main controller 51 (step S12). End the process. When receiving the control accelerator signal in step S12, the main controller 51 controls the output of the electric motor 24 based on the control accelerator amount corresponding to the received control accelerator signal. The output of the electric motor 24 is controlled in proportion to the control accelerator amount. The main controller 51 is preset with a map representing the output of the electric motor 24 corresponding to the control accelerator amount.

  As described above, when the control accelerator amount is larger than the accelerator lever amount (YES in step S10), the output of the electric motor 24 is controlled based on the control accelerator amount changed to the accelerator lever amount (steps S11 and S12). On the other hand, if the control accelerator amount is not larger than the accelerator lever amount (NO in step S10), the electric motor 24 is based on the control accelerator amount calculated in step S6 or the control accelerator amount set to 0 in step S9. Is controlled (step S12). Therefore, since the output of the electric motor 24 is controlled by the smaller value of the control accelerator amount and the accelerator lever amount, the output of the electric motor 24 becomes a small value, and collision with an obstacle can be suppressed. .

  When the control accelerator amount set to “0” in step S9 is output to the main controller 51 as a control accelerator signal in step S12, the output of the electric motor 24 is controlled to “0”. That is, the driving of the electric motor 24 is stopped and the traveling of the vehicle 1 is stopped.

  As described above, in this process, when the measured obstacle distance L (step S1) is equal to or less than the target stop distance (YES in step S7), the control accelerator signal OFF flag is set to “1” ( Step S8) Until the accelerator 0 release condition is satisfied (YES in Step S4), the control accelerator signal OFF flag is maintained at “1” to forcibly set the control accelerator amount to “0” (Steps S8 and S9). In this case, since the control accelerator amount is always equal to or less than the accelerator lever amount (NO in step S10), the output of the electric motor 24 is controlled based on the control accelerator amount set to “0”. Therefore, the driving of the electric motor 24 is forcibly stopped until the accelerator 0 release condition is satisfied (YES in step S4) and the measured obstacle distance L (step S1) is larger than the target stop distance (NO in step S7). The vehicle 1 is forcibly stopped.

  That is, when it is determined that the vehicle 1 has once become equal to or less than the target stop distance, the accelerator lever amount of the occupant D becomes 0 until the vehicle 1 is separated from the obstacle by a target stop release distance that is larger than the target stop distance. At the same time, until the distance to the obstacle of the vehicle 1 becomes larger than the target stop distance, the drive of the electric motor 24 is forcibly stopped by forcibly setting the control accelerator amount to 0, and the vehicle 1 is stopped. When the vehicle 1 is separated from the obstacle by a target stop release distance that is a safe distance, the electric motor 24 can be driven to allow the vehicle 1 to travel.

  Therefore, as in the past, the incident angle of the ultrasonic wave to the obstacle becomes oblique according to the stationary state of the obstacle, and an error occurs in the measurement distance, or the obstacle easily absorbs ultrasonic waves such as clothes. If the pedestrian is an obstacle unlike a stationary object such as a wall, the distance obtained by adding the distance corresponding to the fluctuation of the obstacle is The actual obstacle distance causes a variation in the measured obstacle distance, and the vehicle 1 stops after determining that the measured obstacle distance is equal to or less than the target stop distance. Due to the variation, it is determined that the vehicle 1 is not less than the target stop distance even though the vehicle 1 is actually less than the target stop distance, and the vehicle 1 collides with an obstacle when the vehicle 1 starts to travel again. To prevent such things Kill.

  In this process described above, after the answer is YES in step S7, the number of times that the distance is equal to or less than the target stop distance is counted, and if the predetermined number of times or less is reached within the predetermined time, the process proceeds to step S9. Good. Thereby, it can suppress that the vehicle 1 repeats start and a stop, and can make passenger | crew D ride comfortable.

  As described above, according to the present embodiment, even if the target stop distance is approached, the vehicle 1 is forcibly stopped until it is separated from the obstacle by the target stop release distance. Since it is possible to travel, collision with an obstacle can be prevented. In addition, the vehicle 1 is prevented from restarting due to an erroneous measurement of the obstacle distance of the distance measuring sensor 20, and the reliability of the driving support device can be improved. Furthermore, since unnecessary start / stop of the vehicle 1 can be suppressed, the ride comfort of the occupant D can be improved.

  Further, according to the present embodiment, since the vehicle 1 can be stably stopped near the target stop distance without the occupant D operating the accelerator lever 33 or the brake lever 34, the occupant D can feel secure. It is possible to increase the convenience and improve convenience.

  Further, the driving support process according to the present embodiment can be executed simply by connecting the collision prevention controller 52 as an accelerator controller to a main controller as a motor control unit of an existing small electric vehicle. It is possible to easily prevent a collision with an obstacle in an existing small electric vehicle. Therefore, the collision prevention controller 52 can realize a driving support process as an optional function for an existing small electric vehicle.

  In addition, the small electric vehicle provided with the driving assistance apparatus according to the present invention is not limited to the vehicle 1 according to the above-described embodiment, and may have another configuration, for example.

1 is a right side view of a small electric vehicle including a travel support device according to an embodiment of the present invention. It is a top view of the small electric vehicle of FIG. It is a front view of the small electric vehicle of FIG. It is a rear view of the small electric vehicle of FIG. It is a perspective view of the handle | steering-wheel of the small electric vehicle of FIG. It is a block diagram which shows schematic structure of the control unit of the small electric vehicle of FIG. It is a flowchart of the driving assistance process which the driving assistance apparatus with which the small electric vehicle of FIG. 1 is provided performs. It is a figure for demonstrating the measurement process of the obstacle distance performed in the driving assistance process of FIG.

Explanation of symbols

1 Small electric vehicle 20 Distance measurement sensor 20a Long range sensor 20b, 20c Short range sensor
23 Power unit 24 Electric motor 26 Control unit 33 Accelerator lever 36 Control panel 37 Maximum speed setting switch 38 Travel direction switch 39 Driving support control ON / OFF switch 51 Main controller 52 Collision prevention controller 53 Accelerator lever operation amount detection sensor 54 Vehicle speed sensor

Claims (3)

A steering wheel having an accelerator lever for steering the front wheel, a seat on which a passenger is seated on the rear of the vehicle body behind the handle, a battery mounted below the seat, and driving the rear wheel with the power of the battery A small electric vehicle comprising an electric motor and a driving support device for controlling the electric motor,
The driving support device detects an obstacle ahead of the vehicle body and measures a distance to the obstacle, an accelerator operation amount detecting means for detecting an operation amount of an accelerator lever, and the measurement Accelerator control means for outputting a control accelerator signal representing the control accelerator amount according to the obstacle distance and the detected accelerator operation amount, and motor control for controlling the output of the electric motor based on the output control accelerator signal Means and
The accelerator control means determines that the accelerator is in an OFF state when the measured obstacle distance is equal to or less than a target stop distance, and determines that the accelerator operation amount is zero until the accelerator OFF state release condition is satisfied. A first control accelerator signal representing,
The motor control means stops the electric motor when receiving the first control accelerator signal,
The accelerator OFF state release condition is at least one of the measured obstacle distance being greater than or equal to a target stop release distance greater than the target stop distance and the accelerator operation amount being 0. A small electric vehicle provided with a driving support device.   The small electric vehicle provided with the driving support device according to claim 1, wherein the accelerator control means is detachable. A steering wheel having an accelerator lever for steering the front wheel, a seat on which a passenger is seated on the rear of the vehicle body behind the handle, a battery mounted below the seat, and driving the rear wheel with the power of the battery A method for controlling a small electric vehicle comprising an electric motor and a driving support device for controlling the electric motor,
A distance measuring step for detecting an obstacle ahead of the vehicle body and measuring a distance to the obstacle; an accelerator operation amount detecting step for detecting an operation amount of an accelerator lever; the measured obstacle distance and the detection; A control accelerator signal output step for outputting a control accelerator signal representing the control accelerator amount in accordance with the accelerator operation amount, and a motor control step for controlling the output of the electric motor based on the output control accelerator signal. ,
The control accelerator signal output step determines that the accelerator is in an OFF state when the measured obstacle distance is equal to or less than a target stop distance, and the accelerator operation amount is zero until the accelerator OFF state release condition is satisfied. A first control accelerator signal representing
The motor control step stops the electric motor when receiving the first control accelerator signal,
The accelerator OFF state release condition is at least one of the measured obstacle distance being greater than or equal to a target stop release distance greater than the target stop distance and the accelerator operation amount being 0. A control method for a small electric vehicle.

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