Control device and electric vehicle

There is provided a control device configured to perform a collision preventing control based on an output of an obstacle detection unit. A risk level determination unit determines a collision risk level based on a distance between the obstacle and the electric vehicle. A control level adjustment unit adjusts a control level of the collision preventing control based on the collision risk level. The control level adjustment unit lowers the control level when a releasing unit configured to temporarily release the collision preventing control is operated by a driver during the collision preventing control and causes the electric vehicle to display presence of the obstacle.

CROSS-REFERENCE TO RELATED APPLICATIONS

The disclosure of Japanese Patent Application No. 2019-012133 filed on Jan. 28, 2019, including specification, drawings and claims is incorporated herein by reference in its entirety.

TECHNICAL FIELD

The present disclosure relates to a control device and an electric vehicle.

BACKGROUND

In a boarding-ride electric vehicle represented by an electric wheelchair such as a power scooter, a driver is often an elderly disabled person. Therefore, chances of derailment or falling on gutters, cliffs, dams, railroad crossings, and roads without guard rails and collisions with obstacles such as road steps, trees, and pedestrians are higher compared with a healthy person.

For example, the following Patent Document 1 discloses a technique of attaching a laser radar or a stereo camera to a front side of a host vehicle (an electric vehicle) to detect an obstacle in front of the host vehicle. In Patent Document 1, when the obstacle is detected in a predetermined region in a traveling direction of the host vehicle, driving assistance (for example, deceleration control and alarm output) is performed to the host vehicle. A degree of the driving assistance is controlled stepwise in accordance with a distance between the host vehicle and the obstacle.Patent Document 1: Japanese Patent Application Publication No. 2014-226194 A

However, the electric vehicle such as the above-mentioned power scooter has mobility of traveling on a sidewalk and is treated as a pedestrian. Therefore, compared with a passenger car traveling on a road, a situation is likely to occur in which an obstacle (a person, a bicycle, or the like) comes from right front, leading to an assumed case where the electric vehicle travels while avoiding the obstacle coming from front. In this case, when the driving assistance described above is strictly performed in order to prevent a collision with an obstacle, vehicle control such as alarm output, deceleration, and stop would be frequently performed each time an obstacle is present in front. Accordingly, the driver (the user) may feel uncomfortable.

SUMMARY

It is at least one of objects of the present disclosure to provide a control device and an electric vehicle that can perform collision preventing control in an electric vehicle such as a power scooter without causing discomfort to a driver.

According to an aspect of the embodiments of the present disclosure, there is provided a control device configured to perform a collision preventing control between an obstacle and an electric vehicle based on an output of an obstacle detection unit which is configured to detect the obstacle within a predetermined range in a traveling direction of the electric vehicle, the control device comprising: a risk level determination unit configured to determine a collision risk level between the obstacle and the electric vehicle based on a distance between the obstacle and the electric vehicle; and a control level adjustment unit configured to adjust a control level of the collision preventing control based on the collision risk level and perform the collision preventing control with the adjusted control level, wherein the control level adjustment unit lowers the control level when a releasing unit configured to temporarily release the collision preventing control is operated by a driver during the collision preventing control and causes the electric vehicle to display presence of the obstacle.

According to another aspect of the embodiments of the present disclosure, there is provided an electric vehicle comprising: an obstacle detection unit configured to detect an obstacle within a predetermined range in a traveling direction of the electric vehicle; a display unit configured to display presence of the obstacle; a control device configured to perform a collision preventing control between the obstacle and the electric vehicle based on an output of the obstacle detection unit; and a releasing unit configured to temporarily release the collision preventing control, wherein the control device includes: a risk level determination unit configured to determine a collision risk level between the obstacle and the electric vehicle based on a distance between the obstacle and the electric vehicle; and a control level adjustment unit configured to adjust a control level of the collision preventing control based on the collision risk level and perform the collision preventing control with the adjusted control level, and wherein the control level adjustment unit lowers the control level when the releasing unit is operated by a driver during the collision preventing control and causes the display unit to display the presence of the obstacle.

With the above configuration, it is possible to perform collision preventing control in an electric vehicle such as a power scooter without causing discomfort to a driver.

DETAILED DESCRIPTION OF THE EMBODIMENTS

Hereinafter, an embodiment of the present disclosure will be described in detail with reference to the accompanying drawings. In the following description, a power scooter for an elderly person will be described as an example of an electric vehicle to which the present disclosure is applied, but the application object may be changed without being limited thereto. For example, the present disclosure may also be applied to other types of electric vehicles such as an electric wheelchair for a person having a disorder in their body. In terms of direction, a driver is the reference, based on which an arrow FR indicates a vehicle front side, an arrow RE indicates a vehicle rear side, an arrow UP indicates a vehicle upper side, an arrow LO indicates a vehicle lower side, an arrow L indicates a vehicle left side, and an arrow R indicates a vehicle right side, respectively. That is, the direction indicated by the arrow FR is a traveling direction of the vehicle.

An electric vehicle according to the present embodiment will be described with reference toFIGS. 1 to 3.FIG. 1is an overall perspective view of the electric vehicle according to the present embodiment.FIG. 2is a perspective view of a handle peripheral configuration of the electric vehicle inFIG. 1as viewed from the driver.FIG. 3is a functional block diagram of the electric vehicle according to the present embodiment. The electric vehicle is not limited to the following configuration and may be modified as appropriate.

First, a schematic configuration of an electric vehicle1according to the present embodiment will be described. As shown inFIG. 1, the electric vehicle1is constituted by a power scooter that travels on a sidewalk. The driver is often an elderly person and the electric vehicle1is treated as a pedestrian for legal purposes. Specifically, the electric vehicle1includes a vehicle body2in which an exterior cover is attached to a vehicle body frame2A. The exterior cover includes a floor portion2B on which the driver places feet, a front cover2C disposed on a front side of the vehicle body, and a rear cover2D disposed on a rear side of the vehicle body.

The vehicle body frame2A constitutes an overall frame part and extends in a front-rear direction. A pair of left and right front wheels3are disposed on the front side of the vehicle body2. A pair of left and right rear wheels4are disposed on the rear side of the vehicle body2. A handle unit10that allows the vehicle to be steered is disposed over the front wheels3.

The front wheels3and the handle unit10are coupled by a steering shaft (not shown). The steering shaft extends up and down. As will be described in detail below, the steering shaft is provided with a steering sensor27(seeFIG. 3) that detects a steering angle of a handlebar11.

The periphery of the steering shaft is covered with a leg shield7. The leg shield7constitutes a part of the exterior cover and rises upward from a front portion of the vehicle body. The leg shield7has a function as a windshield that protects the periphery of the feet of the driver seated on a seat8, which will be described below, so that wind or the like does not directly hit the periphery of the feet.

A front basket6is disposed in front of the leg shield7. The front cover2C is provided below the front basket6to cover the front wheels3from above. As will be described in detail below, a camera28is provided on a front surface of the front cover2C as an obstacle detection unit that detects an obstacle within a predetermined range in the traveling direction of the electric vehicle1. The camera28includes an imaging unit such as a stereo camera or a three-dimensional distance image camera and has a predetermined imaging range within the predetermined range in the traveling direction. In the present embodiment, the predetermined range in a front side in the traveling direction is defined as the detection range (the imaging range) of the obstacle, but the present disclosure is not limited thereto. For example, not only the front side but also a lateral side and a rear side may be set as the predetermined detection range.

The seat8for the driver is disposed over a rear portion of the vehicle body2. The seat8includes a seat cushion8A on which the driver sits, a seatback8B that constitutes a backrest of the driver, and a pair of left and right armrests8C. The seatback8B extends upward from a rear end of the seat cushion8A. The armrests8C are provided on two side portions of the seatback8B.

A motor9and a battery (not shown) for the rear wheels4are disposed below the seat8. The motor9drives the rear wheels4via a differential device (not shown). The motor9is driven by electric power of the battery. The motor9and the battery are covered with the rear cover2D. In addition to the motor9and the battery, various electrical components such as a control device30to be described below and a vehicle speed sensor29(seeFIG. 3) that detects a vehicle speed of the electric vehicle1are disposed inside the rear cover2D.

Next, a detailed configuration of the handle unit10will be described. The handle unit10is rotated by the driver seated on the seat8. As shown inFIG. 2, the handle unit10includes a pair of left and right handlebars11held by the driver and a switch box12in which various operation switches are disposed.

The pair of handlebars11protrude from left and right side surfaces of the switch box12and are bent in a substantially U shape in a plan view. In addition, rearview mirrors13are disposed at right and left corners of the switch box12, separately.

The switch box12is disposed in the middle of the entire handle unit10. The switch box12is equipped with an operation device, a display device, and the like that are necessary for driving the electric vehicle1. Specifically, a power switch14is disposed in the middle of a near upper surface of the switch box12. The power switch14is switched between an ON position and an OFF position by rotation operation. When the power switch14is operated to the ON position, power of the vehicle is turned on, and when the power switch14is operated to the OFF position, the power of the electric vehicle1is turned off.

A pair of accelerator levers15are provided on near right and left surfaces of the switch box12. The accelerator levers15extend towards outside the vehicle from side surfaces of the switch box12in vicinity of grip portions of the handlebars11. The accelerator levers15may be operated by being pressed downward from an initial position. The accelerator levers15perform acceleration in a traveling direction that is selected by a traveling direction switching switch17to be described below. When the accelerator levers15are pressed, the electric vehicle1travels in a predetermined direction, and when hands are released from the accelerator levers15, a brake is applied to the motor9to stop the electric vehicle1.

A brake lever16is provided on a side surface of a front left corner of the switch box12. The brake lever16protrudes leftward and is backward rotatable from an initial position with its base end serving as a starting point. The brake lever16functions as a brake when the electric vehicle1is pushed through hands and functions as a parking brake when the electric vehicle1is parked.

The switch box12is further provided with, on the upper surface thereof, the traveling direction switching switch17, a winker switch18, an alarm switch19, a speed adjustment knob20, a display unit21, an audio switch22, a distance reset switch23, a forward confirmation lamp25, and a rearward confirmation lamp26.

The traveling direction switching switch17is constituted by a toggle switch that is tiltable in the front-rear direction. The traveling direction switching switch17switches the traveling direction of the vehicle to forward or rearward. The traveling direction switching switch17is rotatable between a forward position indicating forward movement and a rearward position indicating rearward movement. The forward and rearward positions of the traveling direction switching switch17are indicated by Pf and Pr inFIG. 2. Pn located between Pf and Pr indicates an intermediate position (a neutral position).

A pair of left and right winker switches18are provided. When the left winker switch18is operated, a left turn is signaled, and when the right winker switch18is operated, a right turn is signaled.

The alarm switch19is constituted by a push-button switch. When the alarm switch19is pressed, an alarm sound is issued from a speaker24.

The speed adjustment knob20is a dial operation unit and is disposed substantially in the middle of the upper surface of the switch box12. By operating the speed adjustment knob20, a maximum speed in the forward movement is adjustable within a predetermined speed range. For example, the maximum speed of the electric vehicle1is adjustable within a range of 2 km/h to 6 km/h.

The display unit21is constituted by a display that displays predetermined information on the electric vehicle1in a timely manner and is disposed in the middle of a front side of the upper surface of the switch box12. The display unit21displays, for example, a traveling speed, a traveling distance (a trip meter), and a charging state of the battery. As will be described in detail below, the display unit21displays a warning when the electric vehicle1may collide with an obstacle in front.

The audio switch22is constituted by a push-button switch and sets an audio guidance function on or off.

The distance reset switch23is constituted by a push-button switch. The distance reset switch23is operated to reset the traveling distance displayed on the display unit21to zero.

The forward confirmation lamp25is turned on when the traveling direction switching switch17is set to the forward position and the electric vehicle1may move forward. On the other hand, the rearward confirmation lamp26is turned on when the traveling direction switching switch17is set to the rearward position and the electric vehicle1may move backward.

The speaker24is provided on a near lower surface of the switch box12. The speaker24issues audio guidance or an alarm. Arrangement locations of the various components mounted on the switch box12are not limited to the examples described above and may be modified as appropriate.

Next, the control device30included in the electric vehicle1will be described with reference toFIG. 3. As shown inFIG. 3, the control device30collectively controls operation of the entire vehicle including various configurations of the electric vehicle1. The control device30includes a processor that executes various types of processing, a memory, and the like. The memory is constituted by a storage medium such as a Read Only Memory (ROM) and a Random Access Memory (RAM) depending on application. The memory stores, for example, a control program that controls the above-described various configurations.

As described above, electric signals output from the various configurations of the electric vehicle1are transmitted to the control device30. For example, an image from the front of the electric vehicle1imaged by the camera28is output to the control device30. The control device30calculates a distance to an obstacle in front of the vehicle based on the image.

A detection value of the vehicle speed sensor29and a detection value of the steering sensor27are output to the control device30. The control device30calculates the traveling speed of the electric vehicle1and the steering angle of the steering wheel unit10based on these detected values.

When an obstacle is detected in the front side in the traveling direction based on such information (output), the control device30according to the present embodiment performs collision preventing control to avoid a collision between the obstacle and the host vehicle (the electric vehicle1). As will be described in detail below, examples of the collision preventing control by the control device30include (1) displaying a warning on the display unit21, (2) issuing an alarm by the speaker24, (3) controlling the motor9to perform braking, and the like.

An example of a control device of an electric vehicle for an elderly person in the related art includes such a device in which a device capable of measuring a three-dimensional shape, for example, a distance image camera, is attached to the electric vehicle. With such an electric vehicle, a failure due to unevenness of a traveling destination is detected, a driver is notified, and vehicle control (vehicle speed control such as deceleration and stop, steering direction control, and the like) determined by a distance from an obstacle, a vehicle speed, or the like is performed.

According to such control, chances of collisions of the vehicle with an obstacle can be reduced for the safety of the driver. However, excessive vehicle control may impair usability. When an obstacle that does not need to be detected is detected, unintended behavior of a user (the driver) is assumed to be caused.

Accordingly, it is desirable to carry out collision preventing control in an electric vehicle such as a power scooter without causing discomfort to a driver. In the present embodiment, the camera28is provided as an obstacle detection unit that detects an obstacle in front of the electric vehicle1in the traveling direction. The control device30performs predetermined collision preventing control based on an output of the camera28. As described above, examples of the collision preventing control include (1) displaying a warning on the display unit21, (2) issuing an alarm by the speaker24, (3) controlling the motor9to perform braking, and the like.

The electric vehicle1further includes a cancel switch33as a releasing unit that temporarily releases the above-described collision preventing control by operation of the driver. The cancel switch33is provided, for example, in the switch box12. The cancel switch33is constituted by a push-button switch. The cancel switch33temporarily releases (cancels) the collision preventing control by being operated by the driver during the collision preventing control.

The control device30includes a risk level determination unit31that determines a collision risk level between an obstacle and the electric vehicle1based on a distance therebetween, and a control level adjustment unit32that adjusts a control level of the collision preventing control based on the collision risk level and performs the collision preventing control with the adjusted control level.

The risk level determination unit31determines the collision risk level based on a risk level region to which the obstacle belongs among a plurality of risk level regions (which may also be referred to as determination regions) preliminarily determined in accordance with the distance to the host vehicle within the imaging range of the camera28in the front side in the traveling direction of the electric vehicle1.

When the cancel switch is operated by the driver during the collision preventing control, the control level adjustment unit32lowers the control level of the collision preventing control described above and causes the display unit21to display presence of the obstacle. For example, a warning prompting the presence of the obstacle is displayed on the display unit21.

According to these configurations, when the driver operates the cancel switch33to temporarily release the collision preventing control during the collision preventing control, it is possible to prevent unnecessary collision preventing control by lowering the control level. At that time, the presence of the obstacle is displayed on the display unit21. By doing so, the presence of the obstacle can be recognized again (recalled) by the driver even if the relatively elderly driver is distracted from the presence of the obstacle after operating the cancel switch33. Therefore, it is possible to appropriately perform the collision preventing control and ensure the safety of the driver without causing discomfort to the driver.

The risk level determination unit31determines the collision risk level based on the distance between the obstacle and the electric vehicle1and an expected path of the electric vehicle1. After the operation of the cancel switch33by the driver, the control level adjustment unit32resumes the collision preventing control on a condition that the collision level is lowered.

According to this configuration, after the driver operates the cancel switch33, the collision preventing control is performed again when the collision risk level is lowered by taking a retreat action from the obstacle via some operation relative to the obstacle. Therefore, even when the driver forgets the fact of temporarily operating the cancel switch33, the collision preventing control can be automatically resumed and the safety of the driver can be further enhanced.

In the above example, the control device30includes the risk level determination unit31and the control level adjustment unit32as a plurality of functional blocks and the functional blocks are merely examples for convenience. The control device30is not limited to these functional blocks and may include other functional blocks. The control device30does not have to explicitly include these functional blocks. The control device30may comprehensively perform various types of control described above. That is, the control device30may comprehensively implement functions of the risk level determination unit31and the control level adjustment unit32.

Herein a relationship between the collision risk level and the collision preventing control according to the present embodiment will be described with reference toFIGS. 4 to 6.FIG. 4is a schematic diagram of determination regions for determining the collision risk level of the collision preventing control according to the present embodiment.FIG. 5is a table showing the collision preventing control (control levels) for each collision risk level according to the present embodiment.FIG. 6is another schematic diagram of the determination regions for determining the collision risk level of the collision preventing control according to the present embodiment.

As shown inFIG. 4, the electric vehicle1serving as the host vehicle is traveling in the middle of a sidewalk W extending forward and backward. The left-right width of the sidewalk W is sufficiently larger than the left-right width of the electric vehicle1. The camera28(seeFIGS. 1 and 3) has a predetermined imaging range A in front of the electric vehicle1with a gap G that is a blind area part separating the range A from the host vehicle. The imaging range A has a trapezoidal shape in a plan view in which the left-right width increases toward the front. The imaging range A is divided into a plurality of regions each constituting the above-described risk level region. The imaging range A is divided into six regions according to the distance from the electric vehicle1. Specifically, the imaging range A includes regions A1to A4in front of the electric vehicle1that have a rectangular shape in a plan view and show the expected path of the host vehicle, and a pair of right and left right triangular regions A0on two sides of the regions A1to A4.

The rectangular regions A1to A4are arranged side by side in a front-rear direction of the sidewalk W and are the regions A1, A2, A3, and A4as approaching the host vehicle from a distant location. Left-right widths of the regions A1to A4are preferably substantially the same as or larger than the left-right width of the host vehicle.

In the present embodiment, the imaging range A divided into the regions A0to A4is stored (set) in the control device30in advance. The control device30(the risk level determination unit) determines the collision risk level based on a position of the obstacle in front of the host vehicle within the imaging range A.

The collision risk level decreases as the distance between the obstacle and the electric vehicle1increases. This is because chances of collisions with the obstacle decrease as the obstacle moves away from the electric vehicle1. For example, inFIG. 4, the collision risk level of a region outside the imaging range A of the camera28is LV0. Further, the collision risk level of the regions A0and A1is LV1. Collision risk levels of the regions A2to A4are LV2 to LV4, respectively. In this way, the collision risk level increases as approaching the electric vehicle1.

In the present embodiment, a type of the collision preventing control to the host vehicle changes according to the determined collision risk level (the control level is adjusted). As shown inFIG. 5, when the collision risk level is LV0, that is, when the obstacle is outside the imaging range A of the camera28, the control level is zero, which refers to a normal state. In this case, the collision preventing control is not performed since no influence would be applied to traveling of the electric vehicle1.

When the collision risk level is LV1, that is, when the obstacle is in the region A0or the region A1, the control level is one, which refers to a warning displayed state. As the specific control content, a warning is displayed on the display unit21to prompt the driver to pay attention. This is based on an idea that a display only would be sufficient since the obstacle is at a relatively distant position relative to the host vehicle. As an example of the warning, it is effective to display a direction, a type, and the like of the obstacle.

When the collision risk level is LV2, that is, when the obstacle is in the region A2, the control level is two, which refers to an alarm notified state. As the specific control content, a warning is displayed on the display unit21, and an alarm sound is further issued from the speaker24to prompt the driver to pay attention. This is based on an idea of notifying the driver of danger by adding an alarm by audio since the obstacle is located closer to the host vehicle as compared with the case of the control level 1. As an example of the alarm, audio guidance such as “please pay attention” or a buzzer sound is effective.

When the collision risk level is LV3, that is, when the obstacle is in the region A3, the control level is three, which refers to a deceleration recommended state. As the specific control content, the electric vehicle1is decelerated in addition to the content of the control level 2. This refers to an idea that, since the obstacle is even closer to the host vehicle as compared with the case of the control level 2, only the alarm display plus the warning issue is insufficient and deceleration control is also performed to avoid a collision. It is more effective to set the alarm to be louder than that of the control level 2 and advance its issuance cycle.

When the collision risk level is LV4, that is, when the obstacle is in the region A4, the control level is four, which refers to a stop recommended state. As the specific control content, the electric vehicle1is stopped instead of the deceleration control of the control level 2. This refers to an idea of stopping the host vehicle to avoid the collision reliably since the obstacle is further closer to the host vehicle as compared with the case of the control level 3 and a collision may occur accompanying the deceleration. It is more effective to set the alarm to be louder than that of the control level 3 and advance its issuance cycle.

In this way, it is possible to implement more appropriate collision avoidance to the host vehicle by properly changing the control level according to the collision risk level. That is, the control level increases as the collision level increases. The variation of the collision risk level and the control level is not limited to the above example and may be changed as appropriate. For example, when a plurality of different obstacles in the same direction are detected, an obstacle that is closer to the host vehicle may be given priority. When there are a plurality of obstacles in another direction, an obstacle that is closest to the host vehicle may be given priority. As described above, by setting the collision risk level of the region A0outside the regions A1to A4that are the expected path of the host vehicle to LV1, it is possible to provide a safe state without impairing comfortable driving performance for the driver. The region A0may be alerted when, for example, there is a gutter on a side of the sidewalk W.

After the collision preventing control is performed, the driver may avoid the obstacle or release the collision preventing control. For example, when the driver visually recognizes an obstacle, it is assumed that the driver feels uncomfortable about the collision preventing control (unnecessary alarm or deceleration). Therefore, the present embodiment provides the following control release method.

(1) Obstacle Out of Predetermined Region Due to Steering Operation of Driver

For example, in a case of an obstacle in the region A2ofFIG. 4, the regions A0to A4change in accordance with the steering angle of the electric vehicle1when the driver performs a steering operation, as is shown inFIG. 6. InFIG. 6, by switching the handlebars11to the right, the regions A1to A4, which are the expected path of the host vehicle, change in a curved shape toward the right side. As a result, an obstacle B exits the region A2and now belongs in the region A0. In this case, the control device30, instead of issuing an alarm as the collision preventing control of the control level 2, lowers the control level to one and performs control to display only a warning on the display unit21since the obstacle B belongs to the region A0. Accordingly, an alarm by audio is released and the discomfort to the driver can be eliminated.

When the collision risk level is LV2 to LV4, the driver may temporarily release the collision preventing control by operating the cancel switch33. In this case, the control device30resumes the collision preventing control on a condition that the collision risk level is equal to or lower than LV1. When the collision risk level is LV2 or LV3, the collision preventing control can be canceled even when the host vehicle is traveling. When the collision risk level is LV4, the collision preventing control cannot be canceled until the host vehicle is stopped. Accordingly, discomfort to the driver can be eliminated.

(3) No Intention of Traveling

When the driver stops traveling while the collision risk level is LV1 to LV3, the control level is set to one or the collision preventing control is ended. This is because it can be said that chances of collisions with an obstacle are reduced by stopping the host vehicle.

(4) Completely Turned Off Collision Preventing Control

When the driver has confidence in driving and does not want to use any collision preventing control, the collision preventing control may be completely stopped (that is, fixing the collision risk level always to LV0) by long-pressing the cancel switch33. Complete cancellation of the collision preventing control is set only at the time of stop of the host vehicle.

In this way, in the present embodiment, the driver can avoid a collision before the vehicle is stopped, for example, by performing the collision preventing control using the expected path of the electric vehicle1, the imaging range of the camera28, and the distance between the obstacle and the host vehicle. Therefore, it is possible to perform a smooth operation without deceleration or stop due to unnecessary vehicle control. Further, it is possible to ensure the safety of the driver in advance by warning the driver with the display unit21or the like of the presence of the obstacle in the front side in the traveling direction of the host vehicle while traveling. Further, the driver can avoid the obstacle by themselves before the vehicle is stopped by distinguishing the collision risk level and the control level in accordance with the position of the obstacle so that excessive vehicle control can be prevented. In addition, it is possible to prompt the driver to avoid the obstacle since the driver is notified of a danger level stepwise.

Next, a control flow according to the present embodiment will be described with reference toFIGS. 7 and 8.FIGS. 7 and 8show examples of the control flow according to the present embodiment. In the following flows, unless otherwise specified, operation (calculation, determination, and the like) is performed mainly by the control device30. In control flows shown inFIGS. 7 and 8, it is assumed that the processing from “start” to “end” is repeated at predetermined time intervals.

First, a flow of the collision preventing control will be described. As shown inFIG. 7, when the control is started, in step ST101, the control device30determines whether an obstacle is detected. For example, the control device30can determine whether the obstacle is detected based on whether the obstacle is in the imaging range A of the camera28. When the obstacle is detected (step ST101: YES), the process proceeds to step ST102. When no obstacle is detected, that is, no obstacle is within the imaging range A (step ST101: NO), the collision preventing control is not necessary, the collision risk level is LV0, and the control is ended.

In step ST102, the control device30calculates the collision risk level. Specifically, the risk level determination unit31determines (calculates) the collision risk level based on a region to which the obstacle belongs among the regions A0to A4, in addition to the distance between the obstacle and the host vehicle, the steering angle of the handlebars11, the vehicle speed, and the like. Then, the process proceeds to step ST103.

In step ST103, the control device30performs the collision preventing control at a control level corresponding to the determined collision risk level. The specific control content is as described above. Accordingly, the control ends.

Next, a temporary release and resumption flow of the collision preventing control will be described. InFIG. 8, it is assumed that some collision preventing control is performed in advance. As shown inFIG. 8, when the control is started, in step ST201, the control device30determines whether the cancel switch33was operated (pressed) by the driver. When the cancel switch33was operated (step ST201: YES), the process proceeds to step ST202. When the cancel switch33is not operated (step ST201: NO), the control is ended.

In step ST202, the control device30determines whether the collision preventing control of the control level 4 is being performed. When the collision preventing control of the control level 4 is being performed (step ST202: YES), the process proceeds to step ST203. When the collision preventing control of the control level 4 is not being performed (step ST202: NO), the process proceeds to step ST207.

In step ST203, the control device30determines whether the electric vehicle1is stopped. When the electric vehicle1is stopped (step ST203: YES), the process proceeds to step ST204. When the electric vehicle1is not stopped (step ST203: NO), the processing of step ST203is repeated. That is, step ST203is a step of waiting until the vehicle is stopped by automatic braking.

In step ST204, the control device30lowers the control level to one and performs the collision preventing control. Then, the process proceeds to step ST205.

In step ST205, the control device30determines whether the collision risk level is equal to or lower than LV1. When the collision risk level is equal to or lower than LV1 (step ST205: YES), the process proceeds to step ST206. When the collision risk level is not equal to or lower than LV1 (step ST205: NO), the processing of step ST205is repeated. That is, step ST205is a step of waiting for the collision risk level to decrease to LV1 by an avoidance action of the driver themselves.

In step ST206, the control device30resumes the temporarily released collision preventing control and performs normal vehicle control. Then, the control ends.

In step ST207, the control device30determines whether the collision preventing control of the control level 2 or 3 is being performed. When the collision preventing control of the control level 2 or 3 is being performed (step ST207: YES), the process proceeds to step ST204to immediately lower the control level to perform the collision preventing control of the control level 1. When the collision preventing control of the control level 2 or 3 is not being performed (step ST207: NO), the collision preventing control of the current control level 1 is being performed and the control is ended as it is.

In this way, in the present embodiment, after being temporarily canceled, the collision preventing control is automatically resumed on the condition that the control level is lowered. According to this configuration, it is possible to prevent the driver from forgetting to resume the collision preventing control. Since the collision preventing control is automatically resumed, manual resumption is not necessary each time the driver operates the cancel switch33. This is because it would be troublesome for the driver to manually resume the collision preventing control each time. For example, when obstacles (pedestrians, bicycles, or the like) always come in front at a busy place, the collision preventing control is canceled and resumed each time the driver passes an obstacle after the above control is canceled once, making the operation troublesome.

When the control level is in the alarm notified state (2) or the deceleration recommended state (3), the control level adjustment unit32immediately sets the control level to the warning displayed state (1), and when the control level is in the stop recommended state (4), the control level is set to the warning displayed state (1) on the condition that the electric vehicle is stopped. In this way, when the control level is two or three, the collision preventing control can be canceled even during traveling of the vehicle, whereas when the control level is four, the collision preventing control can be canceled under the condition that the vehicle is stopped. This is for ensuring avoidance time for prompting the avoidance action by the driver and a braking distance of the electric vehicle1because the obstacle is very close to the host vehicle when the control level is four.

As described above, according to the present embodiment, it is possible to perform collision preventing control in the electric vehicle1such as a power scooter without causing discomfort to the driver.

The above embodiment describes the camera28as an example of the obstacle detection unit, but the present disclosure is not limited thereto. A sensor such as a laser radar may be adopted as the obstacle detection unit. In this case, it is preferable for the laser radar to have a predetermined illuminating range in front of the vehicle.

The above embodiment describes a case where the camera28has the imaging range A having a trapezoidal shape in a plan view in the front side in the traveling direction of the electric vehicle1, but the present disclosure is not limited thereto. For example, an omnidirectional camera having a circular imaging range in a plan view may be used.

In the above embodiment, the division method of the plurality of risk level regions may be changed as appropriate. The number and arrangement locations of the regions are not limited to those described above, and a plurality of regions may be divided in a road width direction (left-right direction), for example. Further, an overlap part may be provided at a boundary of adjacent regions, and hysteresis may be provided during control switching. Accordingly, frequent control switching can be prevented.

The above embodiment describes a person or a bicycle as an example of the obstacle, but the present disclosure is not limited thereto. The obstacle may include anything that hinders the traveling of the electric vehicle1such as a step or a wall.

Although the present embodiment and the modification have been described, they may be combined in whole or in part as another embodiment of the present disclosure.

Embodiments of the present disclosure are not limited to the above embodiment and various changes, substitutions and modifications may be made without departing from the scope of the technical idea of the present disclosure. Further, the present disclosure may be implemented by use of other methods as long as the technical concept of the present disclosure can be implemented by the methods through advance of technology or other derivative technology. Accordingly, the present invention cover all embodiments that may fall within the scope of the technical idea of the present invention.

As described above, the present disclosure has such an effect that collision preventing control can be performed in an electric vehicle such as a power scooter without causing discomfort to a driver, and is particularly useful for a control device and an electric vehicle.