KR101794838B1

KR101794838B1 - Active safety system for a personal mobility vehicle

Info

Publication number: KR101794838B1
Application number: KR1020160027086A
Authority: KR
Inventors: 김창원; 서준호; 김정기
Original assignee: 한국기계연구원
Priority date: 2016-03-07
Filing date: 2016-03-07
Publication date: 2017-11-09
Also published as: KR20170104267A

Abstract

The active safety system for personal moving means includes a sensor unit, a determination unit, and a control unit. The sensor unit includes a plurality of sensor modules to sense a traveling environment of the moving means. The determination unit may include a traveling environment determination unit and a collision risk determination unit for determining a traveling environment and a collision risk based on the information sensed by the sensor modules, and a collision risk determination unit for determining a collision risk based on braking control and steering control And a control method determining unit for selecting at least one of the plurality of control methods and determining the control method. The control unit may include an alarm control unit for performing an alarm to the user according to the determination of the collision risk of the determination unit, a braking control unit for controlling the braking of the moving unit or the steering of the moving unit according to the control method determined by the determination unit, And a steering control unit.

Description

{ACTIVE SAFETY SYSTEM FOR FOR PERSONAL MOBILITY VEHICLE}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an active safety system, and more particularly, to an active safety system applied to a personal mobility vehicle at a localized low speed such as an electric wheelchair, an electric scooter or the like.

BACKGROUND ART Conventionally, active safety systems or active safety techniques have been applied to automobiles, and are characterized by automatic braking or automatic steering of the vehicle.

Korean Patent Registration No. 10-1286466, for example, discloses a technology relating to an ACC device that responds quickly through automatic braking, automatic steering, or alarm when a stationary object appears suddenly in front of the vehicle while driving, Japanese Patent No. 10-1511861 discloses a technology relating to emergency braking or automatic steering control by determining whether a collision is expected from a relative distance and a relative speed with respect to a target object.

However, in most cases, the above-described technologies are applied only to automobiles, and expensive sensors and expensive control systems are often required. As a result, there are limitations and limitations in applying to a low-speed personal transportation device such as an electric wheelchair or an electric scooter. Up to now, an automatic braking or automatic steering system applied to such a low- There is no state.

In particular, in the case of a low-speed personal vehicle for a short distance, the main user is a disabled person or an elderly person, so that the environment can not be perceived relatively easily and can be greatly affected by a relatively small impact or impact. There is a need to approach differently, but there are few such studies to date.

Korean Patent No. 10-1286466

Korean Patent No. 10-1511861

SUMMARY OF THE INVENTION Accordingly, the present invention has been made keeping in mind the above problems occurring in the prior art, and an object of the present invention is to provide an active safety system that can be applied to a local moving vehicle at a low speed.

According to an embodiment of the present invention, an active safety system includes a sensor unit, a determination unit, and a control unit. The sensor unit includes a plurality of sensor modules to sense a traveling environment of the moving means. The determination unit may include a traveling environment determination unit and a collision risk determination unit for determining a traveling environment and a collision risk based on the information sensed by the sensor modules, and a collision risk determination unit for determining a collision risk based on braking control and steering control And a control method determining unit for selecting at least one of the plurality of control methods and determining the control method. The control unit may include an alarm control unit for performing an alarm to the user according to the determination of the collision risk of the determination unit, a braking control unit for controlling the braking of the moving unit or the steering of the moving unit according to the control method determined by the determination unit, And a steering control unit.

In one embodiment, the moving means may be an electric wheelchair, an electric scooter or a personal mobility vehicle.

In one embodiment, the sensor modules include an ultrasonic sensor or an infrared (IR) sensor that senses the distance to the obstacle, a vison sensor that senses the shape of the obstacle, an acceleration sensor that senses the velocity or acceleration of the moving means A sensor, and a GPS sensor for sensing the position of the moving means.

In one embodiment, the IR sensor is fixed to face the ground and senses the state of the ground. When the information about the distance sensed by the IR sensor is suddenly above or below a threshold, It can be judged that there is a dull part or a cliff part on the ground.

In one embodiment, the traveling environment determination unit determines whether the moving means is indoor or outdoor, and the control method determining unit determines a control method for performing both the braking control and the steering control on the indoor driving. The control method can be determined so as to perform the braking control.

In one embodiment, when the braking control is performed, the collision risk determination unit determines the automatic braking state if the time to collision (TTC) is less than the time to brake (t _B ) The braking control unit automatically controls the moving means,

TTC = (distance to obstacle) / (velocity of moving means)

t _B = (braking distance) / (speed of moving means)

Lt; / RTI >

In one embodiment, when the braking control is performed, the collision risk determination unit determines the collision risk state when the collision risk (TTC) is less than the collision alarm level (time to warning, t _Bw ) Lt; / RTI >

t _Bw = t _B + t _r (reaction time)

Lt; / RTI >

In one embodiment, when the steering control is performed, the collision risk determination unit determines that the collision risk (TTC) is less than the time to steer (t _S ), and determines that the steering control unit Automatically steers the moving means,

t _S = t _reduce (deceleration time) + t _LPS (final steering time)

t _LPS =

(S _y : side avoidance distance, a _y : lateral acceleration)

Lt; / RTI >

In one embodiment, when the steering control is performed, the collision risk determination unit determines that the collision risk (TTC) is less than the time to steering warning ( _tsw ) Alert avoidance,

t _Sw = t _S + t _r (reaction time)

Lt; / RTI >

In one embodiment, when the steering control is performed, when the speed of the moving means is the following condition,

(v: speed of moving means, r: radius of rotation, mu: friction coefficient, g: gravitational acceleration)

The braking control section may control the steering of the moving means in the steering control section after decelerating the speed of the moving means.

According to the embodiments of the present invention, the braking is automatically controlled or the steering is automatically controlled by judging the traveling environment of the traveling means, and in particular, when the traveling means travels in the room in the electric wheelchair, the electric scooter or the personal traveling means And an optimum control considering the driving environment in the case of traveling outdoors can be performed.

Particularly, since the control method is determined based on whether the moving means travels indoors or outdoors, the danger of rollover is relatively small even if steering is performed at a relatively low speed in the room, And the risk of overturning increases when the vehicle travels at a relatively high speed in the outdoors, so that only the braking control is performed, so that the safety according to the automatic control of the moving means can be further improved.

In this case, an ultrasonic sensor, an IR sensor, a vision sensor, an acceleration sensor, and a GPS sensor, which can sufficiently monitor the driving environment of the personal moving means, are used without mounting an expensive sensor used for control of a general vehicle , It is possible to perform braking control or steering control at a relatively low cost.

On the other hand, since the IR sensor and the vision sensor are vulnerable to the sunlight, only the braking control is performed in the case of moving outdoors, and in addition to the braking control in the room where the sunlight is relatively weak, .

Further, taking into account that the personal moving means can be easily rolled over even by the barb and the cliff part of the ground, the safety of the personal moving means can be further improved by sensing the ground state by fixing the IR sensor facing the ground.

Furthermore, by introducing the concept of collision risk, automatic braking degree, collision warning degree, automatic steering degree and avoidance alarm degree in braking control and steering control, the automatic braking or automatic steering It is possible to perform stable control of the moving means while applying a relatively simple control method.

In addition, in the steering control, in particular, since the personal moving means has a high risk of rollover, the safety of the personal moving means can be improved by performing the braking control prior to the steering control when the speed of the moving means is greater than a predetermined value.

1 is a block diagram illustrating an active safety system according to an embodiment of the present invention.
Fig. 2 is a schematic diagram showing an example of a personal moving means to which the active safety system of Fig. 1 is applied.
3 is a flowchart showing a control state of the drive control unit according to the driving environment judgment of the driving environment judging unit of the active safety system of FIG.
4 is a schematic diagram showing a braking control state of the braking control unit of the active safety system of Fig.
5 is a schematic diagram showing a steering control state of the steering control unit of the active safety system of FIG.
6A and 6B are schematic diagrams showing the sensing state of the IR sensor of the active safety system of FIG.

While the present invention has been described in connection with what is presently considered to be the most practical and preferred embodiment, it is to be understood that the invention is not limited to the disclosed embodiments. It is to be understood, however, that the invention is not intended to be limited to the particular forms disclosed, but on the contrary, is intended to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the invention. Like reference numerals are used for like elements in describing each drawing. The terms first, second, etc. may be used to describe various components, but the components should not be limited by the terms.

The terms are used only for the purpose of distinguishing one component from another. The terminology used in this application is used only to describe a specific embodiment and is not intended to limit the invention. The singular expressions include plural expressions unless the context clearly dictates otherwise.

In the present application, the term "comprises" or "comprising ", etc. is intended to specify that there is a stated feature, figure, step, operation, component, But do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, parts, or combinations thereof.

Unless defined otherwise, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. Terms such as those defined in commonly used dictionaries are to be interpreted as having a meaning consistent with the contextual meaning of the related art and are to be interpreted as either ideal or overly formal in the sense of the present application Do not.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

1 is a block diagram illustrating an active safety system according to an embodiment of the present invention.

Referring to FIG. 1, the active safety system 10 according to the present embodiment is applied to, for example, an electric wheelchair, an electric scooter or other personal mobility vehicle, And it has a high possibility of overturning due to its high center of gravity.

In addition, since the price of the personal moving means is not higher than that of the general vehicle, it is necessary that the active safety system for controlling the personal moving means is not required to have a high specification.

The active safety system 10 includes a sensor unit 100, a determination unit 200, and a control unit 300.

The sensor unit 100 includes a plurality of sensor modules, and senses the traveling environment of the moving unit. Specifically, the sensor unit 100 includes a first sensor module 110, a second sensor module 120, and a third sensor module 130 do.

The first sensor module 110 includes a first ultrasonic sensor 111, a first IR sensor 112 and a vison sensor 113, and the second sensor module 120 The second sensor module 121 includes a second sensor module 121 and a second sensor module 122. The third sensor module 130 includes an acceleration sensor 131 and a GPS sensor 132.

The first and second ultrasonic sensors 111 and 121 measure the distances to the obstacles located at the front or the side when the moving means travels.

As with the ultrasonic sensors, the first and second IR sensors 112 and 122 may measure a distance to an obstacle located at the front or the side when the moving means travels. In the present embodiment, However, it is possible to measure a barb protruding from the ground or a cliff embedded in from the ground.

The vision sensor 113 acquires an image of an obstacle located at a front or a side, and senses the shape of the obstacle.

The acceleration sensor 131 senses the speed or the acceleration of the moving means and senses the direction change of the moving means when the moving direction of the moving means changes.

The GPS sensor 132 senses the position of the moving means.

As described above, the sensor unit 100 senses information about the traveling environment of the moving unit on the front side or the side, and provides the sensing unit 200 with the sensing information.

The determination unit 200 determines the driving environment of the moving unit, the risk of collision of the moving unit, and the like based on the sensing information provided from the sensor unit 100.

More specifically, the determination unit 200 includes a traveling environment determination unit 210, a collision risk determination unit 220, and a control method determination unit 230.

The traveling environment determination unit 210 determines the traveling environment of the traveling means based on the sensing information provided from the sensor unit 100. [ In particular, it is determined whether the moving means travels indoors or outdoors based on the information about the forward or lateral images obtained through the vision sensor 113.

The collision risk determination unit 220 determines the risk of collision with the obstacle located at the front or the side of the moving unit based on the sensing information provided from the sensor unit 100. In this case, the collision risk determination algorithm in the collision risk determination unit 220 will be described later.

The control method determining unit 230 determines the control method for the moving unit to perform both the braking control and the steering control when the traveling environment determining unit 210 determines that the moving unit is traveling in the room, And determines a control method for the moving means so as to perform only braking control when it is determined that the moving means travels outdoors.

As described above, the control method determining unit 230 determines the control method based on whether the moving means travels indoors or outdoors. Therefore, even if steering is performed at a relatively low speed in the room, So that the risk of overturning increases as the vehicle travels at a relatively high speed in the outdoors, so that only the braking control is performed, so that the automatic control of the moving means The safety can be further improved.

The control unit 300 controls the operation of the movement unit based on the determination of the determination unit 200.

The control unit 300 includes an alarm control unit 310 and a drive control unit 320. The drive control unit 320 includes a braking control unit 321 and a steering control unit 322. [

The alarm control unit 310 performs an alarm to the user or the outside according to the determination of the collision risk determiner 220. [

The braking control unit 321 automatically controls the braking of the moving means according to the determination of the collision risk determiner 220 when the control method determining unit 230 determines the braking control method.

Likewise, when the control method is determined by the control method determining unit 230, the steering control unit 322 automatically controls the steering of the moving unit according to the determination of the collision risk determiner 220 .

In this case, the specific control algorithm in the alarm control unit 310 and the drive control unit 320 will be described later.

Fig. 2 is a schematic diagram showing an example of a personal moving means to which the active safety system of Fig. 1 is applied.

Referring to FIG. 2, the active safety system 10 according to the present embodiment may be mounted on the moving means 20 as shown in FIG.

That is, the first sensor module 110 and the second sensor module 120 may be attached to both sides of the body portion 21 of the moving means 20, respectively. In this case, although not shown, the third sensor module 130 may be attached to one side of the body 21 or the body 21.

2, the first and second sensor modules 110 and 120 are attached to the both sides of the body part 21, respectively, by the first ultrasonic sensor 111. Thus, The first ultrasonic sensing area 101 is sensed and the second ultrasonic sensing area 102 is sensed by the second ultrasonic sensor 112 and the first IR sensing area 104 is similarly sensed by the first IR sensor 112. [ And the second IR sensing area 105 is sensed by the second IR sensor 122 so that the front sensing area or the side sensing area which is sensed by the sensor sensing part 100 as a whole can be widened.

In this case, the vision sensor 113 can sense, for example, an area indicated by the vision sensing area 103.

3 is a flowchart showing a control state of the drive control unit according to the driving environment judgment of the driving environment judging unit of the active safety system of FIG.

Referring to FIG. 3, in the active safety system 10, when a sensing signal is transmitted to the traveling environment determination unit 210, the traveling environment determination unit 210 determines whether the traveling means travels indoors or outdoors (Step S10).

Thus, as described above, if it is determined that the vehicle is to be driven outdoors, the control method determining unit 230 determines a control method to perform the braking control (step S30).

On the other hand, if it is determined that the vehicle is traveling indoors, the driving environment determining unit 210 further determines whether the moving means is moving (Step S20), and the control method determining unit 230 considers the moving state And determines the control method to perform the braking control or the steering control (step S40 or step S50).

4 is a schematic diagram showing a braking control state of the braking control unit of the active safety system of Fig.

Hereinafter, an algorithm for performing braking control in the braking control section 321 of the active safety system 10 will be described with reference to FIG.

Referring to FIG. 4, when the moving means travels in a safe driving state indoors or outdoors, the warning, the braking, and the left and right signals are kept off (Step S101).

Meanwhile, the collision risk determiner 220 calculates a time to collision (TTC) based on the sensing information provided from the sensor unit 100 according to the following equation (1). In this case, The smaller the risk of collision, the closer the collision is and the more dangerous the situation is.

TTC = (distance to obstacle) / (velocity of moving means) (1)

In this case, the collision risk determiner 220 compares the collision risk with the time to warning (t _Bw ) defined by the following equation (2), and if the collision risk is smaller than the collision alarm level, (S102). Thus, the moving means corresponds to a collision alarm state, and the alarm control unit 310 alerts a collision on an alarm.

t _Bw = t _B (automatic braking degree) + t _r (reaction time)

In this case, the time to brake (t _B ) is defined by the following equation (3).

t _B = (braking distance) / (speed of moving means) (3)

On the other hand, if the collision risk is greater than the collision alarm level, the collision alarm state (S102) returns to the safe running state (S101).

Further, after the collision alarm state (S102), the collision risk determination unit 220 compares the collision risk with the time to brake (t _B ) defined by the equation (3) If the degree of braking is smaller, it is determined that the braking state is the automatic braking state (S103). Thus, the moving means corresponds to the automatic braking state, and the braking control unit 321 automatically controls the moving means, and accordingly, the warning, the braking, and the left and right signals It remains on.

On the other hand, when the predetermined time t _hold (for example, the time required for taking necessary measures after braking) has elapsed after the automatic braking state (S103), the moving means returns to the safe running state S101), and the warning light, the braking light, and the left and right signals are kept off.

As described above, the braking control unit 321 can automatically control the moving unit, but can more effectively control the moving unit based on a relatively simple calculation algorithm.

5 is a schematic diagram showing a steering control state of the steering control unit of the active safety system of FIG.

Hereinafter, an algorithm for performing steering control in the steering control unit 322 of the active safety system 10 will be described with reference to FIG.

Referring to FIG. 5, when the moving means travels from a room to a safe running state, all the warning, steering, and left and right signals remain off (Step S201).

In the meantime, the collision risk determiner 220 calculates the collision risk (time to collision) TTC according to the equation (1), and calculates the collision risk as a time to steering warning , t _Sw ). If the collision risk is smaller than the avoidance alarm level, it is determined to be the avoidance alarm state (S202). Thus, the moving means corresponds to the avoidance alarm state, and the alarm control unit 310 alerts the user to turn on the warning.

t _Sw = t _S (automatic steerability) + t _r (reaction time)

In this case, the time to brake (t _S ) is defined by the following equation (5).

t _S = t _reduce (deceleration time) + t _LPS (final steering time)

In this case, the final steering time t _LPS is defined by the following equation (6).

t _LPS =

(S _y : side avoidance distance, a _y : lateral acceleration)

On the other hand, if the collision risk is greater than the avoidance alarm level, the avoidance alarm state (S202) returns to the safe running state (S201).

Further, as compared with the avoidance alarm condition (S202) Next, the collision risk determination unit 220, the collision risk the formula (5), the automatic steering is also (time to steer, t _S) defined as in, collision risk is automatically If the degree of steering is smaller than the predetermined steering angle, it is determined to be an automatic steering state (S203). Accordingly, the moving means corresponds to the automatic steering state, and the steering control unit 322 automatically steers the moving means, and accordingly, the steering, the steering, the left and right signals, All remain on.

On the other hand, when the predetermined time t _hold (for example, a time required for taking necessary measures after steering) has elapsed after the automatic steering state (S203), the shifting means is returned to the safe running state S201), and the warning light, the steering light, and the left and right signals are kept off.

As described above, the steering control unit 322 can automatically steer the moving unit, and can automatically steer the moving unit more effectively based on a relatively simple calculation algorithm.

On the other hand, in the case where the automatic braking in the braking control unit 321 and the automatic steering in the steering control unit 322 are performed in the indoor, if the above-described conditions are satisfied in the algorithm for braking, .

Further, when the steering control is performed by the steering control unit 322 with automatic steering, there is a high possibility that the steering is suddenly performed, particularly the moving means has a relatively high center of gravity, and thus overturning occurs.

Accordingly, in the present embodiment, when steering control is performed by the steering control unit 322, the braking control unit 321 performs braking control in advance to perform steering in a state where the speed of the moving means is reduced .

That is, if the speed of the moving means satisfies the following formula (7), the braking control section 321 performs braking control for reducing the speed of the moving means, and then the steering control section 322 performs steering control .

6A and 6B are schematic diagrams showing the sensing state of the IR sensor of the active safety system of FIG.

Referring to FIGS. 6A and 6B, the first IR sensor 112 or the second IR sensor 122 is fixed to the paper surface 30 to sense the state of the paper surface 30.

The collision risk determiner 220 determines the continuity of the distance information based on the distance information from the ground 30 sensed by the first or second IR sensor 112 or 122, If the distance information is equal to or greater than a predetermined threshold value, a cliff 32 is formed on the ground 30 if the distance information is equal to or greater than a preset threshold value. .

Thus, the control unit 300 performs the braking control or the steering control as described above based on the determination result of the collision risk determiner 220.

It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit or scope of the present invention as defined by the following claims. It can be understood that it is possible.

The active safety system according to the present invention has industrial applicability that can be used in local and low-speed personal moving vehicles.

10: active safety system 100: sensor unit
110: first sensor module 120: second sensor module
130: Third sensor module 200:
210: Driving environment determination unit 220: Collision risk determination unit
230: Control method determining unit 300:
310: alarm control unit 320:
321: Brake control section 322: Steering control section

Claims

A sensor unit including a plurality of sensor modules for sensing a traveling environment of the moving means;
A collision risk determination unit for determining a collision risk, and a braking control and a steering control for an indoor running on the basis of the information sensed by the sensor modules, wherein the traveling environment determination unit determines whether the moving means is indoor or outdoor, And a control method determining unit for determining a control method for performing braking control when the vehicle is in an outdoor driving state; And
A braking control unit for controlling the braking of the moving unit or a steering control unit for controlling the steering of the moving unit according to the control method determined by the determining unit, An active safety system including a control unit including a control unit.

The method according to claim 1,
Characterized in that said moving means is an electric wheelchair, an electric scooter or a personal mobility vehicle.

The sensor module according to claim 1,
An ultrasonic sensor or an infrared (IR) sensor for sensing a distance to an obstacle;
A vison sensor for sensing the shape of the obstacle;
An acceleration sensor for sensing the speed or acceleration of the moving means; And
And a GPS sensor for sensing the position of said moving means.

The method of claim 3,
The IR sensor is fixed to face the ground to sense the state of the ground,
Wherein the collision risk judging unit judges that a barrier or a cliff is present on the ground if the information about the distance sensed by the IR sensor is above or below a threshold.

delete

2. The method according to claim 1, wherein, when the braking control is performed,
The collision risk judging unit judges the automatic braking state when the collision risk (time to collision, TTC) is less than the time to brake (t _B ), the braking control unit automatically controls the moving means,
TTC = (distance to obstacle) / (velocity of moving means)
t _B = (braking distance) / (speed of moving means)
Wherein the active safety system comprises:

7. The method according to claim 6, wherein, when the braking control is performed,
The collision risk judging unit judges that the collision risk (TTC) is less than the collision alarm level (time to warning, t _Bw ), the collision avoidance unit warns the collision,
t _Bw = t _B + t _r (reaction time)
Wherein the active safety system comprises:

2. The steering control apparatus according to claim 1, wherein, when the steering control is performed,
The collision risk determination unit determines that the collision risk (TTC) is less than an automatic steering angle (time to steer, t _S ), and the steering control unit automatically steers the moving unit,
t _S = t _reduce (deceleration time) + t _LPS (final steering time)
t _LPS =

(S _y : side avoidance distance, a _y : lateral acceleration)
Wherein the active safety system comprises:

9. The method according to claim 8, wherein, when the steering control is performed,
The collision risk judging unit judges that the collision risk (TTC) is less than the time to steering warning ( _tsw ) and determines that the vehicle is in the avoidance alarm state,
t _Sw = t _S + t _r (reaction time)
Wherein the active safety system comprises:

9. The method according to claim 8, wherein, when the steering control is performed,
When the speed of the moving means is the following condition,

(v: speed of moving means, r: radius of rotation, mu: friction coefficient, g: gravitational acceleration)
Wherein the braking control portion controls the steering of the moving means in the steering control portion after decelerating the speed of the moving means.