KR20120067762A - The collision avoidance apparatus using low-speed and close-range collision avoidance algorithm for active safety - Google Patents

Abstract

The present invention relates to a laser sensor-based low-speed short-range collision avoidance system, comprising: a speed sensor for calculating a relative distance with a preceding vehicle by using a time from the preceding vehicle to being received after being reflected from the preceding vehicle; A sensor unit including a steering wheel sensor and a brake pedal sensor to determine whether the driver recognizes the danger of the driver and the speed of the vehicle and the relative distance between the speed sensor and the preceding vehicle received from the sensor unit; After calculating the speed and acceleration of the preceding vehicle, the vehicle model unit for maintaining the relative distance to the preceding vehicle, the speed of the preceding vehicle, the acceleration, the speed of the own vehicle, the acceleration information in a database; A collision diagnosis unit for determining a collision risk using the database information of the vehicle model unit; A collision warning unit for generating a collision alarm according to the collision risk received from the collision diagnosis unit; And a vehicle control unit controlling an actuator for decelerating the vehicle according to the collision risk received from the collision diagnosis unit. It provides a laser sensor-based low-speed short-range collision avoidance system comprising a.
According to the present invention, by using a laser sensor that is mainly used for industrial precision measurement can increase the measurement accuracy at a short distance, and through the ultrasonic sensor to prevent collision from the front blind spot and the side to prevent the collision from the four stages according to the criteria of the collision risk By applying the situation step by step, the active safety can be improved by preventing sudden stop or deceleration of the car.

Description

The Collision Avoidance Apparatus Using Low-Speed And Close-range Collision Avoidance Algorithm For Active Safety}

The present invention relates to an apparatus for preventing short-range collisions at low speed for active safety using ultrasonic sensors, and more particularly, to avoid collisions that may occur at short distances when the vehicle is operated at low speeds in a crowded city, and further actively to safety. By using the laser sensor on the front of the vehicle and the ultrasonic sensors mounted on both edges of the front of the vehicle, the collision risk can be judged more accurately by detecting the distance, relative speed, relative acceleration and the presence of the side vehicle. The present invention relates to a collision avoidance device using a low-speed short-range collision avoidance algorithm for active safety that actively brakes a vehicle.

Recently, the automobile has been developed as an intelligent vehicle that can provide improved 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 below 30km / h. Radar applied to the existing cruise control devices has a large error in near distance, so it has a low near-field 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 used a laser sensor with excellent short-range accuracy in radar, which was used for obstacle detection in the past, but such near-collision avoidance technology is actually a dense vehicle on domestic roads with much more traffic than overseas. It is difficult to apply in side collisions due to spacing or frequent lane changes. Also, there is a problem in that detection errors due to the use of a laser sensor sensitive to environmental changes and blind spots occurring at the front edge that the laser sense cannot reach are detected. there was.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and can compensate for the occurrence of inaccurate information and front blind spots of the laser sensor sensitive to the environment and distance from the front vehicle measured from the laser sensor on the front of the vehicle. The collision avoidance algorithm according to the collision risk calculated using the values measured from the sensor and the sensor detecting the driver's braking intention to avoid the vehicle collision approaching from the side by using the ultrasonic sensor mounted on the front edge of the vehicle. It is an object of the present invention to provide a collision avoidance apparatus using a low-speed short-range collision avoidance algorithm for active safety to perform the control according to.

The short-range collision prevention device at low speed for active safety using the ultrasonic sensor of the present invention for achieving the above object, the laser sensor for calculating the relative distance with the preceding vehicle using a laser sensor to measure the speed of the driving vehicle A speed sensing unit including a Bluetooth OBD; and a sensor unit including a handle sensor and a brake pedal sensor for determining whether the driver recognizes a dangerous vehicle and an ultrasonic wave for detecting a vehicle approaching to the side; and the speed detecting unit and the sensor unit Calculate the speed and acceleration of the preceding vehicle using the relative distance from the preceding vehicle, the presence or absence of the vehicle on the side, and the speed and acceleration of the own vehicle, and then compare the relative distance with the preceding vehicle, the speed, acceleration, and own vehicle of the preceding vehicle. Vehicle model unit for maintaining the speed, acceleration information, the presence of side obstacles in the database; A collision diagnosis unit for determining a collision risk using the database information of the vehicle model unit; A collision warning unit for generating a collision alarm according to the collision risk received from the collision diagnosis unit; And a vehicle control unit for controlling the actuator to decelerate the vehicle according to the collision risk received from the collision diagnosis unit.

In addition, the database is limited to the size of the memory allowable by the microcontroller, and if the memory capacity is exceeded, the database is kept up to date while deleting the old data and continuously updating with the latest data. It is done.

In addition, the database stores information on the acceleration diagram and the deceleration diagram of the preceding vehicle and the own vehicle using the relative distance with the preceding vehicle, the speed of the preceding vehicle, the acceleration, the speed of the own vehicle, and the acceleration information. .

In addition, the database stores the average deceleration of the driver that can occur at a specific speed and a specific distance in a table form using the relative distance to the preceding vehicle, the speed of the preceding vehicle, the acceleration, the speed of the own vehicle, the acceleration information. It is done.

In addition, the distance value which is a criterion for determining the collision risk is characterized in that it is based on 2.5m.

In addition, the collision risk is composed of four stages of safety stage, warning stage, deceleration stage, and dangerous stage. It is characterized by a step-by-step increase.

According to the collision avoidance device using the low-speed short-range collision avoidance algorithm for active safety according to the present invention, the laser sensor of the center of the front of the vehicle and the ultrasonic sensor and the driving vehicle of both edges of the front of the vehicle in the low-speed near-vehicle operation in the city Ultrasonics mounted on the front edge of the vehicle that can supplement the front laser sensor and front blind spot by using the information obtained through the Bluetooth OBD for measuring the speed and acceleration of the driver and the steering wheel sensor and brake pedal sensor to determine the driver's control will It can improve the reliability of measurement accuracy by using sensors, prevent the collision of blind spots and sides at the front edge, and apply the four stages step by step according to the collision risk judgment criteria to effectively and actively brake the vehicle. Sudden car collision with collision avoidance algorithm By Gina preventing the deceleration can improve active safety.

1 is a block diagram of a vehicle of a low-speed short-range collision prevention device for active safety according to the present invention,
Figure 2 is a low-speed short-range collision avoidance device collision prevention device for active safety according to the present invention,
3 is an exemplary view showing the speed and distance of two vehicles according to the present invention;
4 is a flow chart of four steps according to the criteria for determining the risk of collision according to the present invention;
5 is an algorithm of a low-speed short-range collision avoidance apparatus using an ultrasonic sensor according to the present invention.

Hereinafter, the configuration and operation of an embodiment of a low-speed short-range collision avoidance device for active safety using the ultrasonic sensor according to the present invention with reference to the exemplary drawings in detail.

Referring to FIG. 1, in order to prevent a short-range collision between a vehicle driving at a low speed on a busy road in a city center according to an exemplary embodiment of the present invention, an active device equipped with a laser sensor, an ultrasonic sensor, a Bluetooth OBD, a steering wheel sensor, and a brake pedal sensor is installed. The construction of the low speed short-range collision avoidance device for safety is provided on both front edges of the vehicle so as to compensate for the shortcomings of the laser sensor 10 and the laser sensor attached to the front of the vehicle in order to measure the distance from the vehicle ahead. It is mounted on the steering wheel and the brake pedal sensor 50 installed on the brake pedal so as to detect the collision detection of the driver and the Bluetooth OBD 40 located in the middle of the steering wheel and the brake to detect the speed of the vehicle and the attached ultrasonic sensor 20, respectively. From the handle sensor 60 and the information of the sensor, the determination of the collision situation and the risk may be performed to generate an appropriate signal. The electronic control device 30 is composed of a brake controller 70 for performing the deceleration by the signal generated by the electronic control device and a warning device 80 for generating a warning sound.

As shown in FIG. 2, a low-speed short-range collision preventing device for active safety equipped with an ultrasonic sensor according to an exemplary embodiment of the present invention includes a speed detecting unit 100, a sensor unit 110, a vehicle model unit 120, The collision diagnosis unit 130, the collision warning unit 140, and the vehicle control unit 150.

The speed detecting unit 100 is a laser module unit 101 that detects the relative speed and the relative acceleration of the preceding vehicle through a laser sensor installed at the front center of the vehicle, and a handle and a pedal for measuring the speed and acceleration of the driving vehicle. The measured value is transmitted from the Bluetooth OBD 107 installed in the vehicle model unit 121.

The laser module 101 includes a laser diode and a laser oscillator 103, optical lenses (Tx, Rx) 102, which are responsible for laser transmission and reception, in order to calculate the relative distance between the current vehicle and the preceding vehicle. Is composed of a signal processing unit 104, a TOF algorithm calculation unit 105, and a laser side network module 106 for changing the digital value into a digital value.

The laser light oscillated by the laser diode and the laser oscillator 103 is reflected by the preceding vehicle in front and returns to the laser module through the receiving lens 102. At this time, the received laser light is converted into a digital value through the signal processing unit 104, and the digital value is calculated using the TOF algorithm calculation unit 105 that calculates the relative distance using the time from the laser oscillation to the reflection and reception. It will be output as a digital distance value. The laser side network module 106 transmits a relative distance to the preceding vehicle measured by the laser module unit 101.

As shown in FIG. 3, the distance between the two cars is d, the speed of the preceding vehicle is V ₂ , the speed of the following vehicle is set to V ₁ , and the speed of the following vehicle is set to V ₁ in the laser module unit 101. The acceleration of the vehicle is A ₂ , the acceleration of the following vehicle is A ₁ , and the relative speed between the two vehicles is defined as ΔV and the relative acceleration as ΔA.

ΔV Is equal to V ₂ minus V _1, and ΔA Is equal to A ₂ minus A ₁ .

The sensor unit 110 includes an ultrasonic sensor on both sides of the front edge of the vehicle and a handle sensor mounted on a handle capable of determining the control intention of speed according to a driver's risk recognition, and a brake pedal sensor mounted on a brake pedal. .

The ultrasonic sensors 111 are mounted on each side of the front edge of the vehicle so as to detect obstacles within 2.5m and side obstacles within 3m, which are blind spots of the laser sensor, and provide information on the detection of obstacles. It transmits to the model part 121.

The steering wheel sensor 112 and the brake pedal sensor 113 detect a momentary large change in the steering wheel and the brake pedal so as to determine whether the driver is aware of the danger of collision of the vehicle. The determination is sent to the vehicle model unit 121 to determine the driver's response to the risk determination step.

The vehicle model unit 120 uses information transmitted from the speed detecting unit 100 and the sensor unit 110 to determine information on the acceleration diagram and the deceleration diagram of the vehicle in order to analyze the risk and determine the collision situation. Included in the form of a database.

In order to determine the collision situation and analyze the risk, it is necessary to first measure the braking distance of the ideal vehicle to select the appropriate distance to follow the preceding vehicle.

을 이용하고 이 식에서 사용된 마찰계수 μ= 0.8을 이용하여 도심 혼잡교통 내의 평균 주행속도인 20km/h일 때의 요구되는 제동거리를 계산하면 D = 1.96m 와 같은 값을 구할 수 있다.Expression for braking distance

By calculating the required braking distance at 20km / h, the average driving speed in urban congested traffic, using the coefficient of friction μ = 0.8 used in this equation, we can obtain a value equal to D = 1.96m.

In order to prevent collision in actual driving at the braking distance obtained here, the distance to determine the risk of collision was selected as 2.5m.

The collision risk technique proposed in the present invention is applied step by step according to the relative speed, relative acceleration and the distance between the vehicles.

First, relative velocity (△ V) and relative acceleration (△ A) are divided into greater than zero, equal to zero, and less than zero, which is a factor for predicting the amount of change in the distance between vehicles. Judging how much you lose, determine your risk.

Next, the risk factor is determined by the distance factor between the two vehicles. The risk level is set based on the safety braking distance 2.5m specified above. That is, three collision risk judgment factors are used to determine the collision risk using speed, acceleration, and distance between vehicles.

Each situation was set based on the following criteria.

1. In ΔV> 0 and ΔA> 0 situations, designate the safety level regardless of the distance between vehicles.

2. In case of ΔV <0, ΔA <0, it is designated as a dangerous step regardless of the distance between vehicles.

3. Whenever the relative speed, relative acceleration, or distance between vehicles becomes worse, the safety situation is upgraded by one level based on the safety stage, the safest situation.

[Table 1] can be completed through the above three conditions. [Table 1] shows the collision risks according to the relative speed, relative acceleration, and distance value.

ΔV> 0 ΔV = 0 ΔV <0 Dmax = 2.5 m 2.5m or less Dmax = 2.5 m 2.5m or less Dmax = 2.5 m 2.5m or less ΔA> 0 Safety level Safety level Safety level Safety level Warning step Risk level ΔA = 0 Safety level Safety level Safety level Warning step Risk level Crash phase ΔA <0 Safety level Safety level Warning step Risk level Crash phase Crash phase

The safest state, the safety phase in which the collision avoidance system does not work, the preparation phase in preparation for the intervention of the collision avoidance system, the warning phase informing the driver of the danger without controlling the actuator, and the deceleration in which the brake pressure is adjusted to adjust the pressure. Stages, and finally the most dangerous situation, divided into dangerous stages that require stopping.

Referring to FIG. 4, in each situation, the collision avoidance system selects a control method suitable for the current situation.

In the safety phase, the current state is safe, but there is a point where it is impossible to guarantee a safe distance over time, so the anti-collision device is operated to measure the situation.

The warning step is to judge whether the collision can be substantially avoided by the collision avoidance device. If the driver's control intention is first determined from the steering wheel sensor and the brake pedal sensor, the warning step is converted to safety level again. If there is no willingness to control, it is a step that informs the driver of the hazard through steering wheel vibration or warning sound and requires control.

At the risk level, the driver controls the actuator while adjusting the brake pressure to 50%, reducing the safety braking distance while decelerating in the range that does not impair the driver's riding comfort, and waiting for the driver's control or with the preceding vehicle. Decelerate according to the distance change.

Finally, the collision stage is a stage in which collision is inevitable by the driver, and a stop is required. The actuator is controlled to adjust the brake pressure to 100% so that the vehicle can be stopped as soon as possible.

By applying each of the four stages step by step, it prevents a sudden stop or deceleration of the car and requires the driver to control, so that it does not interfere with the driver's driving and does not cause a sudden change in the crowded traffic.

The vehicle model unit 121 is used for collision determination using the relative distance ΔD of the front vehicle received from the laser module unit 101 through the speed information V ₁ and the acceleration information A _{1 of the} own vehicle. The speed V ₂ and the acceleration A ₂ of the front vehicle to be calculated are calculated. The speed information, acceleration information, and relative distance of the vehicle ahead are updated in the database of the vehicle model unit 121 at regular intervals during the driving time. The amount of data in this database is limited by the amount of memory that the microcontroller can accept, keeping the database up-to-date while deleting past data beyond the memory capacity and continuing to update with the latest data.

The database includes ΔD, V ₁ , V ₂ , A ₂ , Using the A ₁ information, match the driver's average deceleration (range from -1g to 0g: g = -9.81m / s ² ) that can occur at a specific speed and a specific distance and store it in the form of a table. Because each driver has different relative distances and decelerations to keep ahead of the vehicle, the table gradually tunes the system to suit the driver's driving preferences as he drives.

Since the vehicle model unit 121 using the database can predict the vehicle speed and the acceleration in the next cycle in advance by using the change trend of the speed and the acceleration, it helps to make a quick collision determination.

The collision diagnosis unit 120 is the speed of the own vehicle stored in the database of the vehicle model unit 121, the acceleration and the speed of the preceding vehicle, the acceleration information and relative distance, the presence or absence of side vehicles and obstacles, the degree of collision recognition of the driver By using the collision risk determination table [Table 1] of the present invention to determine the possibility of collision and transmits the collision risk information. The collision risk information is used by the collision warning unit 130 and the vehicle control unit 140 according to the possibility of collision risk.

The collision warning unit 130 decelerates the driver's deceleration will by deciding whether the collision risk level received through the collision warning unit network module 131 is a warning stage or a deceleration stage based on information from the steering wheel sensor and the brake pedal sensor. If there is no willingness to warn the driver through a warning sound or handle vibration in the case of the driver, the decelerating phase to operate the brake pressure pedal 50% through the vehicle control unit 140, if the collision phase vehicle control unit 140 The brake pressure pedal is operated 100% to stop the vehicle in the shortest possible time.

The vehicle controller 140 controls the actuator 150 using the braking controller 142 and the servo driver 143 to decelerate the vehicle according to the collision risk.

According to the present invention, it is possible to increase the measurement accuracy at a short distance by using a laser sensor, and detect the collision of the vehicle from the front blind spot and the side through the ultrasonic sensor and apply the situation in four stages according to the collision risk judgment criteria. Therefore, active safety can be improved by preventing a sudden stop or deceleration of the vehicle.

In the present specification, a preferred embodiment of the low-speed short-range collision preventing device for active safety using the ultrasonic sensor according to the present invention has been described, but the present invention is not limited thereto. The invention may be practiced in various ways within the scope of the claims and the accompanying drawings, which also belong to the scope of the invention.

100 Speed Sensor 101 Laser Module
102 Receiver lens 103 Laser diode and laser oscillator
104 Signal Processing Unit 105 TOF Algorithm Computing Unit
106 Laser side network module 107 Bluetooth OBD
110 sensor section 111 ultrasonic sensor
`112 Handle sensor 113 Brake pedal sensor
120 Collision diagnosis unit 121 Vehicle model unit
122 Network module 130 collision warning part
131 Network module of collision warning unit 140 Vehicle control unit
141 Network module at vehicle control unit 142 Brake controller
143 Servo Drive 150 Actuator

Claims (6)

Collision avoidance device using low speed near collision avoidance algorithm for active safety,
A speed sensor including a laser sensor for calculating a relative distance to the preceding vehicle and a Bluetooth OBD for measuring the speed of the driving vehicle;
A sensor unit including a steering wheel sensor and a brake pedal sensor for detecting a vehicle approaching the front blind spot and the side of the laser sensor and determining whether the driver is willing to control the ultrasonic sensor for effective active control;
After calculating the speed and acceleration of the preceding vehicle using the relative distance between the speed detecting unit and the preceding vehicle received from the sensor unit, the presence or absence of the vehicle on the side and the speed and acceleration of the own vehicle, the relative distance with the preceding vehicle, A vehicle model unit for maintaining the speed, acceleration, speed of the own vehicle, acceleration information, and the presence of side obstacles of the preceding vehicle in a database;
A collision diagnosis unit for determining a collision risk using the database information of the vehicle model unit;
A collision warning unit for generating a collision alarm according to the collision risk received from the collision diagnosis unit;
Vehicle control unit for controlling the actuator to decelerate the vehicle in accordance with the collision risk received from the collision diagnosis unit; collision prevention apparatus using a low-speed short-range collision avoidance algorithm for active safety. The method of claim 1,
The database is limited to the size of the memory allowable by the microcontroller, and if the capacity of the memory is exceeded, the database is kept up to date while deleting the old data and continuously updating the latest data. Collision avoidance device using low speed near collision avoidance algorithm for active safety. The method of claim 1,
The database stores active safety and acceleration information of the preceding vehicle and the own vehicle using the distance from the preceding vehicle, the speed of the preceding vehicle, the acceleration, the speed of the driving vehicle, and the acceleration. Anti-collision device using low speed near field collision avoidance algorithm. The method of claim 1,
The database may store the average deceleration of the driver that may occur at a specific speed and a specific distance in a table form by using a relative distance from the preceding vehicle, the speed of the preceding vehicle, the acceleration, the speed of the own vehicle, and the acceleration information. Collision avoidance device using low speed near collision avoidance algorithm for active safety. The method of claim 1,
The collision prevention apparatus using a low-speed short-range collision avoidance algorithm for active safety, characterized in that the distance value which is a criterion for determining the collision risk is based on 2.5m. The method of claim 1,
The collision risk is composed of four stages: safety stage, warning stage, deceleration stage, and dangerous stage, and the risk situation is one stage whenever the situation of relative speed, relative acceleration, or inter-vehicle deteriorates based on the safety stage, which is the safest situation. An anti-collision device using a low-speed short-range collision avoidance algorithm for active safety characterized in that it increases.

Images