KR101285350B1 - Collision avoidance apparatus with adaptive type laser sensor and method using the same - Google Patents

Abstract

PURPOSE: A collision prevention device for a vehicle including an adaptive type laser sensor and a collision prevention method using the same are provided to accurately measure a distance from a vehicle in front by controlling an emitting angle of a laser beam. CONSTITUTION: A collision prevention device of a vehicle includes a laser sensor (110), a front ultrasonic sensor (120), a steering angle sensor (130), a controller (140), and a side ultrasonic sensor (150). The laser sensor is installed on the front of a driving vehicle and includes a beam emitting unit, a beam receiving unit, and a beam driving unit. The steering angle sensor measures a steering angle of the driving vehicle. The controller calculates a distance from a vehicle in front by using a time until the laser beam is reflected from the vehicle in front and returns. The controller finds the arc length of a curved road corresponding to a straight distance from the vehicle in front based on the measured steering angle and calculates the distance from the vehicle in front. [Reference numerals] (111) Beam emitting unit; (112) Beam receiving unit; (113) Beam driving unit; (121) Sound wave generating unit; (122) Sound wave sensing unit; (123) Sound wave driving unit; (130) Steering angle sensor; (140) Controller

Description

Collision avoidance apparatus with adaptive type laser sensor and method for preventing collision using same

The present invention relates to a collision avoidance device for a vehicle that can prevent collision at a low speed short distance, and in particular, accurate aiming and distance measurement using a laser sensor for a preceding vehicle traveling along a curved road as well as on a straight road. The present invention relates to a collision avoidance device for a vehicle having an adaptive laser sensor and a collision avoidance method using the same.

In general, the collision avoidance device refers to a safety device that can prevent or avoid a collision of the vehicle.

Recently, the automobile has developed into an intelligent vehicle that can provide more safety and convenience by using advanced information and communication technology as well as improving fuel economy and performance as a means of transportation. However, intelligent cars have many functions such as entertainment systems, air purifiers, and convenience devices, so that the driver can operate an increased control device in addition to the control device for driving, thereby increasing the risk of driving due to the carelessness of the driver. It was. Accordingly, various studies have been made on safety devices for preventing or avoiding a vehicle crash on a busy city road due to momentary carelessness.

Representative examples include the Adaptive Cruise Control System, the Forward Vehicle Collision Warning System, and the Lane Departure Warning System. The pedals are controlled by a microprocessor. This constant speed driving system is currently controlled by ON / OFF method and is mainly used in high-speed driving of 40km / h or more due to the characteristic of 24GHz FMC radar. Most of the technology to detect obstacles.

However, most of the actual traffic accidents occur in urban areas because more than 70% of traffic accidents occur at low speeds of less than 30km / h. Radar applied to the existing cruise control devices has a large error in near distance, so low-speed near collision It is not suitable for constructing a prevention system, and in case of a close collision occurring in a low speed situation, it is more affected by the princess distance required for driver recognition than the braking distance required for braking.

Recently, the City Safety function introduced by Volvo is a laser sensor that emits and receives a laser beam by using a laser sensor with excellent short-range accuracy by switching from a radar that has been widely used for obstacle detection. It is a trend that is being adopted to detect or measure distance.

However, in the case of such a laser sensor 11, as shown in FIG. 1, when the vehicle 10 travels on a curved road, a preceding vehicle in which a laser beam having a straight propensity turns along the curved road and has already rotated in another direction There was a problem in that it could not detect the preceding vehicle or measure the distance because it could not aim accurately.

Accordingly, the present invention has been proposed to solve the conventional problems as described above, and an object of the present invention is to precisely aim and measure distance using a laser sensor not only on a straight road but also on a preceding vehicle traveling along a curved road. The present invention provides a collision avoidance apparatus for a vehicle having an adaptive type laser sensor and a collision avoidance method using the same.

In order to achieve the above object, an anti-collision device for a vehicle according to the technical spirit of the present invention includes a beam light emitting unit installed at a front portion of a traveling vehicle and emitting a laser beam, and a laser beam that is reflected and returned after being emitted. A laser sensor including a light receiving unit for receiving light and a beam driving unit for rotating the beam light emitting unit to adjust an emission angle of a laser beam; A steering angle sensor for measuring a steering angle of the traveling vehicle; And a controller for calculating a distance to the preceding vehicle by using the time until the laser beam is reflected from the preceding vehicle and returning. The driving angle is measured based on the steering angle measured by the steering angle sensor when driving the curved road. The technical configuration features that the laser beam can be aimed and measured on the preceding vehicle located on the curved road by adjusting the emission angle of the laser beam.

Here, the controller calculates an arc length of a curved road corresponding to a straight line distance to the preceding vehicle based on the measured steering angle and calculates the arc length of the curved road based on the measured steering angle to use the distance from the preceding vehicle. It can be characterized.

In addition, the light emitting angle of the laser beam may be characterized in that the angle is larger than the steering angle of the driving vehicle in consideration of the distance that the preceding vehicle first moved along the curved road.

In addition, the plurality of laser sensors are provided with a plurality of spaced apart from each other, the laser beam emission angle of each laser sensor may be characterized in that they are different from each other so as to widen the detection range for the preceding vehicle.

In addition, the sound wave generator is installed in the front portion of the traveling vehicle, and emits an ultrasonic wave forward, and a sound wave detection unit for receiving the ultrasonic wave emitted from the sound wave generator after being reflected back to detect the preceding vehicle It may be characterized by further comprising a front ultrasonic sensor.

In addition, the front ultrasonic sensor is usually used to detect the presence of a preceding vehicle approaching the front by assisting the laser sensor, but when the laser sensor is inoperable, the time until the ultrasonic wave is reflected from the preceding vehicle to return. It may be used to calculate the distance with the preceding vehicle by using.

The front ultrasonic sensor may further include a sound wave driver configured to drive the sound wave generator to rotate to adjust the launch angle of the ultrasonic wave, and the controller may adjust the launch angle of the ultrasonic wave based on the steering angle measured by the steering angle sensor. It may be characterized in that for applying a control signal to the sound wave driver.

In addition, near the front edge of the driving vehicle may be characterized by further comprising a side ultrasonic sensor to detect the vehicle approaching from the side by emitting an ultrasonic wave to the side.

The controller may include a distance from a preceding vehicle, a rate of change of a distance from a preceding vehicle, a speed of a driving vehicle, a rate of change of a speed of a traveling vehicle, output information by sensing of the side ultrasonic sensor, and output by sensing of the front ultrasonic sensor. It can be characterized by using the information to find the risk of collisions in stages.

In addition, the collision risk, a safety step means a state without a collision risk, a warning step means a state that requires the attention of the driver is expected to be a collision risk, a collision is expected to require a function to reduce the speed of the driving vehicle partly It may be characterized as being classified into a dangerous stage, which means a state, and a collision stage, which means a state in which a function is required to reduce the speed of the driving vehicle as much as possible in order to avoid a collision since the collision is sure.

In addition, when the collision risk is calculated by the output information of the front ultrasonic sensor, the collision risk step may be upgraded one step higher than when the collision risk is obtained by the output information of the side ultrasonic sensor.

In addition, the output information of the front ultrasonic sensor is classified into medium and near according to the sensed proximity of the vehicle, and the speed of the driving vehicle is divided into slow, medium, and fast, and the rate of change of the speed of the driving vehicle is decelerate, keep, and accelerate. When the output information of the front ultrasonic sensor is medium, it is assumed that the vehicle belongs to a dangerous stage when the speed of the driving vehicle is slow and when the speed and the rate of change of the driving vehicle are medium, decelerate, medium and keep, respectively. When the output information of the front ultrasonic sensor is near, it may be characterized as belonging to a collision stage when the speed and the rate of change of the traveling vehicle are medium and accelerated respectively, and when the speed of the traveling vehicle is fast.

In addition, the output information of the lateral ultrasonic sensor is classified into medium and near according to the detected approaching degree of the vehicle, and the speed of the driving vehicle is divided into slow, medium, and fast, and the rate of change of the speed of the driving vehicle is decelerate, keep, accelerate. When the output information of the lateral ultrasonic sensor is medium, it belongs to the warning stage when the speed of the traveling vehicle is slow and when the speed and the rate of change of the driving vehicle are medium, decelerate, medium and keep, respectively. When the output information of the lateral ultrasonic sensor is near, it belongs to the dangerous stage when the speed and the rate of change of the driving vehicle are medium and accelerated respectively, and belongs to the collision stage when the speed of the traveling vehicle is fast. You can do

On the other hand, the vehicle collision avoidance method according to the present invention, by emitting a laser beam for the preceding vehicle, by calculating the distance with the preceding vehicle by using the time until the emitted laser beam is reflected from the preceding vehicle, It is possible to warn of the danger of collision with the preceding vehicle, but when the traveling vehicle is driving on the curved road, the preceding vehicle already turning along the curved road by adjusting the emission angle of the laser beam in response to the steering angle of the driving vehicle. It is the technical configuration features that make it possible to aim.

Here, when calculating the distance with the preceding vehicle, the arc length of the curved road corresponding to the straight line distance with the preceding vehicle may be obtained based on the steering angle of the traveling vehicle and used as the distance with the preceding vehicle.

In addition, the light emitting angle of the laser beam may be characterized in that the angle is larger than the steering angle of the driving vehicle in consideration of the distance that the preceding vehicle first moved along the curved road.

In addition, the light emission of the laser beam may be made of a plurality of laser beams having different wavelengths, and the emission angle of each laser beam is made to be different from each other to extend the detection range for the preceding vehicle. .

In addition, the vehicle emits an ultrasonic wave toward the front of the driving vehicle, and detects only the presence of the preceding vehicle normally. However, in an emergency in which the laser beam cannot emit light, the ultrasonic wave emitted is reflected by the preceding vehicle. It can be characterized in that the distance to the vehicle can be calculated.

The vehicle collision avoidance device and the collision avoidance method using the adaptive type laser sensor according to the present invention, since the light emission angle of the laser beam is adjusted based on the steering angle of the vehicle, the preceding vehicle traveling not only on a straight road but also on a curved road Accurate aiming and distance measurement are also possible.

In addition, since the present invention obtains the distance from the preceding vehicle as the circumferential length of the curved line instead of the linear distance from the preceding vehicle, a more substantial and precise distance can be obtained.

In addition, in the present invention, when the emission angle of the laser beam is determined, the angle is larger than the steering angle of the driving vehicle in consideration of the distance that the preceding vehicle first moves along the curved road, thereby enabling accurate aiming of the preceding vehicle.

In addition, the present invention emits a plurality of different laser beams, by varying the emission angle of each laser beam can be detected in a wider range.

In addition, the present invention includes the distance from the preceding vehicle, the rate of change of the distance from the preceding vehicle, the speed of the driving vehicle, the rate of change of the speed of the driving vehicle, the output information by the detection of the side ultrasonic sensor and the output information by the detection of the front ultrasonic sensor. By using the step-by-step collision risk, it is possible to precisely predict collisions and control the vehicle according to the warning and collision risk.

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a reference diagram for describing the prior art.
Figure 2 is a state of use of the vehicle collision avoidance apparatus according to an embodiment of the present invention.
Figure 3 is a block diagram showing a schematic configuration of a collision avoidance device for a vehicle according to an embodiment of the present invention.
4 is a plan view of a traveling vehicle for showing the arrangement of the laser sensor and the ultrasonic sensor according to an embodiment of the present invention.
5 is a front view of a traveling vehicle for showing the arrangement of the laser sensor and the ultrasonic sensor according to an embodiment of the present invention.
6 is a state diagram used for explaining the configuration of a collision avoidance apparatus for a vehicle according to a modified embodiment of the present invention.
Figure 7 is a graph for explaining the function of the fuzzy inference input values in the vehicle collision avoidance apparatus according to an embodiment of the present invention.
8 to 14 is a series of reference diagrams to support the experiment for the performance evaluation of the vehicle collision avoidance apparatus according to an embodiment of the present invention.

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

2 is a state diagram of use of the collision avoidance apparatus for a vehicle according to an embodiment of the present invention.

As shown, the collision avoidance device for a vehicle according to an embodiment of the present invention does not emit the laser beam L only toward the front of the driving vehicle 100, but enters a curved road in the state of entering the curved road. It is configured to accurately aim the preceding vehicle 20 by adjusting the emission angle of the laser beam L to be bent in association with the steering angle.

As a result, the present invention enables the laser beam L to be aimed at the preceding vehicle 20 when driving along the curved road as well as on the advanced road, thereby making it possible to measure the distance for preventing collision.

Hereinafter, the configuration of a vehicle collision avoidance apparatus according to an embodiment of the present invention will be described.

3 is a block diagram showing a schematic configuration of a collision avoidance device for a vehicle according to an embodiment of the present invention, Figure 4 is a plan view of a driving vehicle for showing the arrangement of the laser sensor and the ultrasonic sensor according to an embodiment of the present invention. . 5 is a front view of a traveling vehicle for showing the arrangement of the laser sensor and the ultrasonic sensor according to an embodiment of the present invention.

As shown, the vehicle collision avoidance apparatus according to an embodiment of the present invention, the laser sensor 110, the laser sensor 110 is configured to be able to adjust the angle of emission of the laser beam (L), assist the laser sensor 110 The vehicle includes a front ultrasonic sensor 120, a steering angle sensor 130, a controller 140, and a lateral ultrasonic sensor 150. The preceding vehicle turns along the curved road even when the traveling vehicle 100 enters the curved road. The distance measurement through the laser beam L with respect to 20 is easily performed.

Hereinafter, the configuration of the collision avoidance apparatus for a vehicle according to an embodiment of the present invention will be described in more detail with respect to each of the above components.

First, the laser sensor 110 is installed in the front part of the traveling vehicle 100 and emits and receives a laser beam L from time to time to detect whether the preceding vehicle 20 is detected and the relative distance to the controller 140. It serves to send electrical signals for To this end, the laser sensor 110 is a beam light emitting unit 111 for emitting a laser beam (L) for the preceding vehicle 20, and a beam light receiving unit for receiving a laser beam (L) that is reflected back after being emitted ( 112 is basically provided, and a beam driver 113 for adjusting the light emitting angle of the laser beam L is provided.

Here, the beam driver 113 is mounted to the base 113a fixed to the front part of the preceding vehicle 20 and rotatably mounted to the left and right sides of the base 113a to adjust the emission angle of the laser beam L. It consists of a mount 113b to be adjustable. The beam light emitting part 111 is provided in the mount 113b. The configuration for the operation of the mount 113b that rotates with respect to the base 113a in the beam driver 113 may be simply a combination of a motor and a reduction gear.

In addition, the beam driver 113 is interlocked with the steering angle sensor 130 with respect to the controller 140, and the beam driver 113 has a larger angle than the steering angle of the driving vehicle 100 measured by the steering angle sensor 130. By rotating the mount 113b, accurate aiming is achieved with respect to the preceding vehicle 20 running ahead on the curved road. If the rotation angle for the aiming of the laser beam L is the same as the measured steering angle, the aiming of the laser beam L may deviate with respect to the preceding vehicle 20 moving along the curved road. Therefore, after determining the detection distance range by the laser beam L in advance, the additional angle according to the steering angle is calculated in consideration of the maximum distance of the detection distance range (about 6-8 m or less), and the emission angle of the laser beam L is calculated. Final decision. This operation is performed by the controller 140.

The front ultrasonic sensor 120 serves to detect when the preceding vehicle 20 approaches the front of the traveling vehicle 100 by assisting the laser sensor 110 mainly used for distance measurement. To this end, the front ultrasonic sensor 120 is installed in the front of the vehicle 100, the sound wave generator 121 for firing ultrasonic waves forward, and is emitted from the sound wave generator 121 and reflected back It consists of a sound wave detection unit 122 for receiving the ultrasonic waves to detect the preceding vehicle (20).

In addition, the front ultrasonic sensor 120 is further provided with a sound wave driver 123 to drive the sound wave generator 121 to rotate to adjust the firing angle of the ultrasonic wave. The reason why the sound wave driver 123 is provided is to replace the role of the laser sensor 110 when the front ultrasonic sensor 120 is inoperable. In this case, the controller 140 calculates the distance from the preceding vehicle 20 by using the time until the ultrasonic wave is reflected from the preceding vehicle 20 and returns, and is measured by the steering angle sensor 130. A control signal for the sound wave driver 123 is applied to adjust the launch angle of the ultrasonic wave based on the steering angle.

On the other hand, the side ultrasonic sensor 150 is installed near the front edge of the traveling vehicle 100. As a result, the ultrasonic wave is emitted toward the side of the traveling vehicle 100 to detect a vehicle approaching from the side.

As described above, according to the exemplary embodiment of the present invention, the laser sensor 110 provided to detect the preceding vehicle 20 and use the distance measurement and the preceding vehicle 20 closer to the front by assisting the laser sensor 110 are provided. Front ultrasonic sensor 120 to detect the vehicle and the side ultrasonic sensor 150 to serve to detect a vehicle approaching from the side is provided with organic use to more close to the collision with the adjacent vehicles Accurately predict and prevent collisions. This will be described later in more detail.

The steering angle sensor 130 serves to measure the steering angle of the traveling vehicle 100. In general, the steering angle sensor is a key component of the steering system of the vehicle. The steering angle sensor detects the rotation angle, direction, and rotation speed applied to the steering wheel, and the vehicle's multifunction control software determines the amount and direction of the auxiliary power required. It is a sensor that provides optimal handle operation and adjusts the suspension and headlights accordingly. Currently, a technology related to such a steering angle sensor is variously known and products that can measure up to 0.1 degrees have been commercialized, so that any one of the commercially available steering angle sensors for the steering angle sensor 130 according to the present invention may be employed. Just do it.

The controller 140 applies a control signal to the beam driver 113 of the laser sensor 110 to adjust the firing angle of the laser beam (L) based on the steering angle measured by the steering angle sensor 130, The laser beam L serves to calculate a distance from the preceding vehicle 20 by using the time from the preceding vehicle 20 to be reflected back.

However, the controller 140 may calculate the arc length of the curved road d2, that is, the arc length of the curved road, instead of the linear distance d1 between the driving vehicle 100 and the preceding vehicle 20 when calculating the distance between the preceding vehicle 20. Obtain To this end, the curved distance d2 is reflected by reflecting the steering angle of the traveling vehicle 100 in the linear distance d1 between the traveling vehicle 100 and the preceding vehicle 20 obtained using the time when the laser beam L is reflected and returned. That is, the curved distance d2 corresponding to the arc length of the curved road can be obtained. This curve distance d2 is the distance to the preceding and correct vehicle 20 on the curve road.

6 is a state diagram used to explain the configuration of a vehicle collision avoidance apparatus according to a modified embodiment of the present invention.

As shown, in the modified embodiment of the present invention, a plurality of laser sensors 110a and 110b are provided at a distance from the front center of the vehicle to the left and right, and the laser beams L1 and L2 of the respective laser sensors 110a and 110b are provided. The light emitting angles are characterized by being different from each other. A described in the drawing is the deviation angle formed by each of the laser beams L1 and L2 emitted from each of the laser sensors 110a and 110b. As the deviation angle A increases, the detection range increases, and conversely, as the deviation angle a decreases, the detection range decreases.

According to such a configuration, as shown in FIG. 6, the detection range of the preceding vehicle 20 can be widened from side to side by the laser beams L1 and L2 that are plurally emitted in a plurality, and thus the preceding vehicle 20 on the curved road. It is possible to detect without missing.

As a result, it is possible to completely solve the problem that the left and right sensing ranges of the laser beams L1 and L2 having the straightness tend to be extremely narrow, and to secure a wide sensing range even without expensive equipment such as a laser scanner. do.

Meanwhile, the plurality of laser sensors 110a and 110b may be configured to emit laser beams L1 and L2 having different wavelengths. For example, even if only the semiconductor laser is considered, the wavelength of the GaAs laser and the CdS laser is divided into 0.84 μm and 0.494 μm, respectively, so that such a configuration can be easily performed.

As a result, when receiving the laser beams L1 and L2 reflected from the preceding vehicle 20, the laser beams L1 and L2 emitted from the plurality of laser sensors 110a and 110b are clearly distinguished. It is possible to determine the exact detection position of the preceding vehicle (20).

The collision avoidance apparatus for a vehicle according to the embodiment of the present invention configured as described above is operated to calculate a collision risk step by step based on fuzzy inference to issue a differential warning or to automatically control the operation of the vehicle. This is explained as follows.

To this end, the controller 140 uses the distance with the preceding vehicle 20 calculated using the laser sensor 110, the distance change rate, the speed and the speed change rate of the driving vehicle, and in addition to the front ultrasonic sensor 120 The collision risk is calculated step by step based on the output information using the lateral ultrasonic sensor 150. The collision risk is classified into four stages, a safety stage, a warning stage, a dangerous stage, and a collision stage, and the differential warning is issued accordingly so that the driver can substantially respond to the collision risk or automatically control the operation of the vehicle. By doing so, collision with the preceding vehicle 20 can be avoided.

Here, the safety step means a state where there is no risk of collision, and the warning step means a state in which attention of the driver is required as a step in which a collision risk is expected. In addition, the dangerous step means a state in which a collision is expected, and a state in which a function of reducing the speed of the driving vehicle 100 is required is required, and the collision step is a step in which the collision is assured, and the speed of the driving vehicle 100 is avoided to avoid the collision. It means the state that needs the function to reduce as much as possible.

By using the output information of the side ultrasonic sensor 150, the output information of the front ultrasonic sensor 120, the distance information with the preceding vehicle 20 by the laser sensor 110, the speed of the traveling vehicle 100, the rate of change of velocity The method of calculating the collision risk with the vehicle 20 in each step is as follows.

Referring to FIG. 7, in the case of the output information u _s (k) by the lateral ultrasonic sensor 150, as shown in (a), the medium and the near are classified according to the detection intensity of the vehicle approaching and detected from the side. The warning level, the risk level, and the collision level are determined by considering other input values.

In the case of the output information u _f (k) by the front ultrasonic sensor 120, as shown in (b), the medium and the near are classified according to the sensing intensity of the vehicle approaching and detected from the front, and other input values are considered. Determine the warning, risk, and crash phases. In the case of the front ultrasonic sensor 120, the collision risk level is upgraded one step higher than when the vehicle is detected by the side ultrasonic sensor 150. This is because the forward movement of the traveling vehicle 100 is much faster than the lateral movement because the collision risk for the front vehicle is much higher than the collision risk for the side vehicle.

In the case of the distance information (d _k (k)) by the laser sensor 110, as shown in (c), 0 to 2m to near, 2 to 4.5m to medium, 4.5 to 6m to far, The safety level, warning level, danger level and collision level are determined by considering other input values for the case. To this end, after performing an initialization process, the speed of the traveling vehicle is measured, and the speed is continuously measured if the measured speed of the traveling vehicle 100 is 30 km / h or more. On the other hand, if the speed of the driving vehicle is 30km / h or less, it is checked whether the laser sensor 110 measures the distance to the preceding vehicle (20). The absence of the distance information of the preceding vehicle 20 in the laser sensor 110 is a case in which no information is received due to an instantaneous error or there is no vehicle within 6 m ahead of the vehicle. In order to determine this, there is no distance information of the preceding vehicle 20. If the error time is greater than the set max error time, it is determined that there is no vehicle ahead, and if it is smaller than that, it is determined that it is caused by an instantaneous error. When the distance information with the preceding vehicle 20 is received, a sudden change caused by the unevenness of the road surface is corrected using a Kalman filter. Next, the distance information and the maximum inter-vehicle distance information (d _max (k)) with the preceding vehicle 20 corrected using the Kalman filter are compared. The maximum inter-vehicle distance information means a distance set in consideration of the safety factor to the minimum stopping distance (D _s ) necessary to stop the vehicle of 30km / h. The minimum stopping distance is calculated by the following equation using the principle that the kinetic energy determined by the speed is the same as the energy consumed by braking.

D _S = (V ² m / 2μg)

Where m is the mass of the vehicle and μ is the coefficient of friction. The coefficient of friction used a value of 0.8 based on dry pavement. The vehicle's speed is calculated as the minimum stopping distance of 4.5m based on 30km / h. For safety reasons, 6m is set as the maximum distance between cars. If the distance information on the preceding vehicle 20 is greater than the maximum inter-vehicle distance, it is determined that there is an error in the distance information, and the process returns to the first step. On the other hand, if the distance information of the preceding vehicle 20 is smaller than the maximum inter-vehicle distance, the collision risk is determined at the step of determining the collision state using fuzzy inference.

In the case of the distance change rate information Δd _k (k), as in (d), -0.15 to 0.15 m is classified as keep, if it is less than the range, it is classified as decrease, and if it is more than the range, it is classified as different. The safety level, warning level, danger level and collision level are determined by considering the input values.

In the case of the speed information (v _m (k)) of the traveling vehicle 100, as in (e), 10 to 22.5 km / h is divided into medium, if less than the range is slow, if more than that range is classified as fast, For each case, the safety level, warning level, danger level and collision level are determined by considering the different input values.

As in the case of the speed change rate information (Δv _m (k)), -2 to 2 m / s ² is kept as a keep, if it is below the range, it is classified as a decrease, if it is above the range, it is classified as an increase, and in each case Consider other input values to determine safety level, warning level, danger level and collision level.

In the collision avoidance apparatus for a vehicle according to an embodiment of the present invention, 51 fuzzy rules are prepared based on the fuzzy input values as described in Table 1 to determine a collision risk step by step.

u _s (k) u _f (k) d _k (k) Δd _k (k) v _m (k) Δv _m (k) c _s (k) One none none far increase x x safety 2 none none far keep x x safety 3 none none far decrease slow x safety 4 none none far decrease medium decelerate safety 5 none none far decrease medium keep safety 6 none none far decrease medium accelerate warning 7 none none far decrease fast decelerate safety 8 none none far decrease fast keep warning 9 none none far decrease fast accelerate warning 10 none none medium increase slow x safety 11 none none medium increase medium x safety 12 none none medium increase fast decelerate safety 13 none none medium increase fast keep safety 14 none none medium increase fast accelerate warning 15 none none medium keep slow decelerate safety 16 none none medium keep slow keep safety 17 none none medium keep slow accelerate warning 18 none none medium keep medium decelerate safety 19 none none medium keep medium keep warning 20 none none medium keep medium accelerate warning 21 none none medium keep fast decelerate warning 22 none none medium keep fast keep warning 23 none none medium keep fast accelerate danger 24 none none medium decrease slow decelerate warning 25 none none medium decrease slow keep warning 26 none none medium decrease slow accelerate danger 27 none none medium decrease medium decelerate warning 28 none none medium decrease medium keep danger 29 none none medium decrease medium accelerate collision 30 none none medium decrease fast decelerate danger 31 none none medium decrease fast keep danger 32 none none medium increase fast accelerate collision 33 none none near Increase Slow x warning 34 none none near Increase medium x danger 35 none none near increase fast x danger 36 none none near keep slow x danger 37 none none near keep medium x collision 38 none none near keep fast x collision 39 none none near decrease x x collision 40 medium x x x slow x warning 41 medium x x x medium decelerate warning 42 medium x x x medium keep warning 43 near x x x medium accelerate danger 44 near x x x fast x danger 45 near x x x x x collision 46 x medium x x slow x danger 47 x medium x x medium decelerate danger 48 x medium x x medium keep danger 49 x near x x medium accelerate collision 50 x near x x fast x collision 51 x near x x x x collision

The fuzzy rules summarized in Table 1 and the collision risks determined by them are briefly described as follows.

The fuzzy rules 1 to 9 are for the case where the distance from the preceding vehicle 20 is far.

In this case, the collision risk is divided into a safety stage and a warning stage, most of which belong to a safety stage. When the collision risk falls within the warning stage, the rate of change of distance decreases and the speed and rate of change of the driving vehicle 100 are medium and accelerated, fast and keep, fast and accelerate, respectively.

The purge rules 10 to 32 are for the case where the distance from the preceding vehicle 20 is medium.

When the rate of change of distance is increased, most of them belong to the safety stage, but they belong to the warning stage when the speed and rate of change are fast and accelerated, respectively.

In addition, if the rate of change of distance is keep, the speed and rate of change are slow and decelerate, slow and keep, medium and decelerate, respectively, and belong to the safety phase, and the rate of change of speed is slow and accelerate, medium and keep, medium and It belongs to the warning stage when accelerated, fast and decelerate, fast and keep, and it belongs to the dangerous stage when speed and rate of change are fast and accelerated respectively.

Also, if the rate of change of distance is decreasing, it belongs to the warning stage when the speed and rate of change are slow and decelerate, slow and keep, medium and decelerate, respectively, and the rate and rate of change are slow and accelerate, medium and keep, fast and It belongs to the dangerous stage when decelerate, fast and keep, and it belongs to the collision stage when the speed and rate of change are medium, accelerate, fast and accelerate respectively.

The purge rules 33 to 39 are for the case where the distance from the preceding vehicle 20 is near.

If the rate of change of distance is increased, it belongs to the warning stage when the speed is slow and belongs to the dangerous stage when the speed is medium or fast.

Also, if the distance change rate is keep, it belongs to the dangerous stage when the speed is slow, and belongs to the collision stage when the speed is medium or fast.

In addition, if the rate of change of distance is decreasing, it belongs to the collision stage regardless of speed or rate of change of speed.

The purge rules 40 to 45 are for the case where the vehicle is detected by the side ultrasonic sensor 150.

If the output information of the lateral ultrasonic sensor 150 is medium, when the speed is slow, it belongs to the warning step when the speed and rate of change rate is medium and decelerate, medium and keep, respectively.

In addition, when the output information of the lateral ultrasonic sensor 150 is near, it belongs to the dangerous stage when the speed and rate of change are medium and accelerated respectively, and belongs to the dangerous stage when the speed is fast, and then the speed and rate of change of speed are When not in the collision phase.

The purge rules 46 to 51 correspond to a case where a vehicle is detected by the front ultrasonic sensor 120. When the vehicle is detected by the front ultrasonic sensor 120, the collision risk is upgraded by one step than when the vehicle is detected by the side ultrasonic sensor 150.

That is, when the output information of the front ultrasonic sensor 120 is medium, when the speed is slow, it belongs to the dangerous stage when the speed and the rate of change are medium and decelerate, medium and keep, respectively.

In addition, when the output information of the front ultrasonic sensor 120 is near, when the speed and rate of change are medium and accelerate, respectively, when the speed is fast, and then there is no speed and rate of change, it belongs to the collision step.

As described above, in the embodiment of the present invention, in addition to using the distance with the preceding vehicle 20 obtained through the laser sensor 110, the distance change rate, the speed and the speed change rate of the traveling vehicle 100 as input values, By using output information using the front ultrasonic sensor 120 and the lateral ultrasonic sensor 150 as an input value, the collision risk is further subdivided into steps. As a result, the collision risk between vehicles can be predicted more realistically and precisely.

Experimental Example: Performance Evaluation of Fuzzy Reasoning-based Collision Room

In this experiment, as shown in Fig. 8, a test vehicle was implemented using a domestic L company G vehicle. The laser sensor installed in the test vehicle as (b) used S80-YL0 model of Data sensor with a sensing distance (l ₁ ) of up to 6m.The front and side ultrasonic sensors mounted on the front bumper were (a) and Similarly, we used SensorTec's automotive STMA-506 model with a sensing distance (l ₂ ) of up to 3m and a sensing range of r _u = 25 °. In particular, the laser sensor is installed at the height of h ₁ = 0.65m from the ground in the outer center of the vehicle in consideration of the characteristic that the error of the distance information can be increased if the glass penetrates. The front ultrasonic sensor and the side ultrasonic sensor were installed at intervals of w ₁ = 60 cm and w ₂ = 30 cm at a height of h ₂ = 0.6 cm from the ground as shown in (c). Here, two front ultrasonic sensors were installed to face the front and side ultrasonic sensors were installed to achieve r _i = 70 °. Finally, the maximum inter-vehicle distance d _max was set to 6m, the measuring distance of the laser sensor.

The laser sensor is connected to the ECU corresponding to the controller in the embodiment of the present invention by using a UART, and the front ultrasonic sensor and the lateral ultrasonic sensor use an interrupt pin and a GPI / O (general purpose I / O) pin. Connected to the ECU. The unit time for calculating the relative speed and the relative acceleration was set as the operation processing cycle of the ECU and set to 100 ms in consideration of the short-range environment. As an OBD device that measures the speed of the vehicle, Free-GPS's free-OBD Plus Mini model was used. In particular, the used OBD device has the advantage that it can be used in various fields because it can receive the speed and information of the driving vehicle wirelessly using Bluetooth. ECUs with built-in collision alarm algorithms were built using Freescale's MC9S-12XF512 with FlexRay and CAN controller. Here, CAN transceiver uses NXP's PCA82C250 and Bluetooth receiving module for OBD data reception uses Firmtech's FB755AX. Finally, Vector's CANoe.FlexRay 7.2 was used to monitor the relevant information.

In order to evaluate the performance of the fuzzy inference based collision avoidance system, three experiments were performed according to the driving conditions of the vehicle. The first experiment evaluated whether the collision avoidance system was operating normally while driving with the preceding vehicle located at a speed below 30 km / h. The second experiment evaluated whether the collision avoidance device would work normally when the vehicle was cut off on the side. In particular, it was confirmed how the front ultrasonic sensor and the laser sensor as well as the side ultrasonic sensor for the vehicle approaching from the side. The final experiment was to collide with an object assuming a stopped vehicle. The final experiment simulates a collision with a vehicle stopping in front due to the carelessness of the driver while driving.

-When driving with a preceding vehicle

9 shows the state of the front ultrasonic sensor and the side ultrasonic sensor (see a), the distance with the front vehicle (see b), the distance change rate (see c), and the speed of the driving vehicle (see d) when the vehicle is driven with the preceding vehicle. , The rate of change of velocity (see e) and the change in collision risk (see f).

As shown in FIG. 9, the collision risk was increased step by step when the distance from the preceding vehicle is reduced and the speed is increased. On the contrary, when the distance from the preceding vehicle increases and the speed decreases, it is confirmed that the collision risk level does not increase but maintains and decreases the warning level. In particular, about 3.4 seconds, the distance from the preceding vehicle is relatively long, but the distance change rate with the preceding vehicle is relatively large, so the collision risk level increases until the collision stage, thereby warning the driver of the danger.

FIG. 10 illustrates an alarm system that visually alerts each collision risk level when driving with a preceding vehicle. As the distance from the preceding vehicle decreases, it is confirmed that the warning device is visually displayed while increasing the collision risk. In particular, in the dangerous stage of (c) and the collision stage of (d), it can be seen that the distance from the preceding vehicle is close enough to require immediate braking.

-When the vehicle cuts in from the side

11 shows the state of the side ultrasonic sensor (see a), the distance from the preceding vehicle (see b), the distance change rate (see c), the speed of the driving vehicle (see d), and the speed change rate when the vehicle is interrupted from the side. and change in collision risk (see f).

As shown in (a), the vehicle to be cut off from the side was detected by the side ultrasonic sensor about 1 second, and the vehicle was moved by the front ultrasonic sensor about 1.7 seconds. At the same time, as can be seen in (b), the distance information with the preceding vehicle 20 by the laser sensor is maintained at 0, and it is confirmed that the value of about 2.445m is instantaneously at about 2.2 seconds. This is because the front ultrasonic sensor detects at a position closer to the vehicle interrupted than the laser sensor.

As shown in (f), the collision risk level increased from the time when the vehicle was caught from the side to warn the driver of the danger, and the collision risk decreased from the time the interrupted vehicle maintained sufficient distance and speed.

FIG. 12 illustrates an alarm system that visually alerts the vehicle to sequentially enter a collision risk level as the vehicle enters the vehicle while driving normally (see a). When the vehicle entering the side was detected by the side ultrasonic sensor, a warning step was made (see b), and then detected by the front ultrasonic sensor, it was confirmed that it increased to the dangerous stage and the collision stage (see c and d).

-Collide with a stationary object

13 shows the state of the front ultrasonic sensor sensor (see a), the distance to the preceding vehicle (see b), the distance change rate (see c), the speed of the driving vehicle (see d), and the speed change rate when the vehicle collides with a stationary object. (see e) and collision risk changes (see f).

As it can be seen in Figure 13, it was confirmed that the collision risk step increases sequentially as the distance to the stationary object decreases. When the distance from the stationary object is about 5.7m, the collision risk level is increased to the warning level, and when the distance is about 4.405m, it increases to the danger level. In particular, from the point where the distance to the stationary object was about 3.078 m, the danger stage increased to the collision stage. After the risk level increased to the collision level, the driver suddenly reduced the speed of the vehicle and then reduced it to the danger level, but after that, it was confirmed that the collision risk level was correctly determined.

FIG. 14 illustrates an alarm device that visually alerts the collision risk level to sequentially increase from the start time to the moment of collision with the stationary object. Even in experiments that collide with stationary objects, as the level of collision risk increases step by step, the alarm system distinguishes between safety level (see a), warning level (see b), danger level (see c), and collision level (see d). Marked by.

Through the above experimental results, the performance of the anti-collision apparatus of the present invention based on fuzzy inference at low speed is verified. In particular, through the experiments of the three cases that can occur in the low-speed short-range driving was verified with the feasibility of the vehicle collision avoidance device proposed in the embodiment of the present invention. In addition, the validity of each stage was indirectly verified by using a warning device visually displayed to the driver for the four stages of the collision risk level.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments. It is clear that the present invention can be suitably modified and applied in the same manner. Therefore, the above description does not limit the scope of the present invention, which is defined by the limitations of the following claims.

110, 110a, 110b: laser sensor 111: beam light emitting unit
112 beam receiving unit 113 beam driving unit
120: front ultrasonic sensor 121: sound wave generator
122: sound wave detection unit 123: sound wave driving unit
130: steering angle sensor 140: controller
150: side ultrasonic sensor

Claims (18)

In a collision avoidance device for a vehicle installed in a traveling vehicle to determine the risk of collision with the preceding vehicle based on the distance between the traveling vehicle and the preceding vehicle,
It is installed in the front part of the traveling vehicle, the beam light emitting unit for emitting a laser beam, the beam light receiving unit for receiving the laser beam that is reflected back after the light emission, and driving to rotate the beam light emitting unit to adjust the emission angle of the laser beam A laser sensor having a beam driving unit;
A steering angle sensor for measuring a steering angle of the traveling vehicle;
And a controller for calculating a distance to the preceding vehicle by using the time until the laser beam is reflected from the preceding vehicle and returned.
When driving on a curved road, the laser beam may be aimed and measured on a preceding vehicle located on the curved road by adjusting the light emitting angle of the laser beam based on the steering angle measured by the steering angle sensor.
The controller calculates an arc length of a curved road corresponding to a straight line distance to the preceding vehicle based on the measured steering angle and calculates the arc length as the distance from the preceding vehicle when calculating a distance from the preceding vehicle on the curved road. Anti-collision device for cars. delete The method of claim 1,
The emission angle of the laser beam is a vehicle collision avoidance device, characterized in that made in the angle greater than the steering angle of the driving vehicle in consideration of the distance that the preceding vehicle first moved along the curved road. The method of claim 1,
The laser sensor is provided with a plurality of spaced apart from each other, the laser beam emission angle of each laser sensor is characterized in that the vehicle collision preventing device characterized in that the deviation from each other so as to widen the detection range for the preceding vehicle to the left and right. The method of claim 1,
The front ultrasonic wave is provided in the front of the traveling vehicle, and composed of a sound wave generator for emitting ultrasonic waves forward and a sound wave detector for receiving ultrasonic waves reflected from the sound wave generator and returned. An anti-collision device for a vehicle, further comprising a sensor. The method of claim 5,
The front ultrasonic sensor is usually used to detect the presence of a preceding vehicle approaching the front by assisting the laser sensor, but when the laser sensor is inoperable, the time for the ultrasonic wave to be reflected back from the preceding vehicle is used. The collision avoidance device for a vehicle, characterized in that it is utilized to calculate the distance with the preceding vehicle. The method according to claim 6,
The front ultrasonic sensor may further include a sound wave driving unit configured to drive the sound wave generator to rotate to adjust the launch angle of the ultrasonic wave, and the controller may adjust the launch angle of the ultrasonic wave based on the steering angle measured by the steering angle sensor. An anti-collision device for a vehicle, characterized in that for applying a control signal to the sound wave driver. The method of claim 5,
And a side ultrasonic sensor configured to detect an approaching vehicle from the side by emitting an ultrasonic wave to the side near the front edge of the driving vehicle. 9. The method of claim 8,
The controller may include the distance from the preceding vehicle, the rate of change of the distance from the preceding vehicle, the speed of the traveling vehicle, the rate of change of the speed of the traveling vehicle, output information by sensing of the side ultrasonic sensor, and output information by sensing of the front ultrasonic sensor. Using a collision avoidance device for a vehicle, characterized in that to obtain a step-by-step collision risk. 10. The method of claim 9,
The collision risk level is a safety step that means a state in which there is no risk of collision, a warning step that means a state in which a driver's attention is required because of a collision risk is expected, and a state in which a function of reducing a speed of a driving vehicle due to a collision is expected is required. Means of danger, a collision prevention device for a vehicle characterized in that it is divided into a collision stage means a state that requires a function to reduce the speed of the driving vehicle as much as possible to avoid the collision. The method of claim 10,
When the collision risk is determined by the output information of the front ultrasonic sensor, the collision avoidance device of the vehicle, wherein the collision risk step is upgraded one step higher than the case of obtaining the collision risk by the output information of the side ultrasonic sensor. The method of claim 11,
The output information of the front ultrasonic sensor is classified into medium and near according to the approaching degree of the detected vehicle, and the speed of the driving vehicle is divided into slow, medium and fast, and the rate of change of the driving vehicle is divided into decelerate, keep and accelerate. So,
When the output information of the front ultrasonic sensor is medium, it is assumed that the vehicle belongs to a dangerous stage when the speed of the driving vehicle is slow and when the speed and the rate of change of the driving vehicle are medium, decelerate, medium and keep, respectively,
When the output information of the front ultrasonic sensor is near, the collision avoidance device for the vehicle characterized in that it belongs to the collision stage when the speed and the rate of change of the vehicle is medium and accelerate, respectively, and when the speed of the vehicle is fast. . The method of claim 11,
The output information of the lateral ultrasonic sensor is classified into medium and near according to the detected approaching degree of the vehicle, and the speed of the driving vehicle is divided into slow, medium, and fast, and the speed change rate of the driving vehicle is divided into decelerate, keep, and accelerate. So,
When the output information of the lateral ultrasonic sensor is medium, it is assumed to belong to a warning step when the speed of the traveling vehicle is slow and when the speed and the rate of change of the driving vehicle are medium, decelerate, medium and keep, respectively,
When the output information of the lateral ultrasonic sensor is near, it belongs to the dangerous stage when the speed and the rate of change of the traveling vehicle are medium and accelerated, respectively, and it belongs to the collision stage when the speed of the traveling vehicle is fast. Vehicle anti-collision device. In the collision avoidance method for a vehicle for calculating the distance from the preceding vehicle, and determining the risk of collision with the preceding vehicle and generating an alarm signal,
By emitting a laser beam to the preceding vehicle and calculating the distance from the preceding vehicle using the time until the emitted laser beam is reflected from the preceding vehicle, the warning of collision with the preceding vehicle can be warned. ,
When the driving vehicle travels on a curved road, the laser beam emission angle is adjusted according to the steering angle of the driving vehicle so that the vehicle can be aimed at the preceding vehicle already turning along the curved road.
And calculating an arc length of a curved road corresponding to a straight line distance with the preceding vehicle based on the steering angle of the traveling vehicle and calculating the arc length of the curved vehicle based on the steering angle of the driving vehicle. delete 15. The method of claim 14,
The emission angle of the laser beam is a collision prevention method for a vehicle, characterized in that made in the angle larger than the steering angle of the driving vehicle in consideration of the distance that the preceding vehicle first moved along the curved road. 15. The method of claim 14,
The emission of the laser beam is made of a plurality of different laser beams, and the emission angle of each laser beam is made to be different with respect to each other so as to widen the detection range for the preceding vehicle. 15. The method of claim 14,
Ultrasonic waves are emitted in front of the driving vehicle to detect only the presence of the preceding vehicle in normal times. However, in case of emergency that the laser beam cannot be emitted, the emitted ultrasonic wave is reflected from the preceding vehicle and is returned to the preceding vehicle. Collision prevention method for a vehicle, characterized in that to calculate the distance.

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