KR101144043B1 - control method for prevention of pedestrian accident using the bluetooth and zigbee - Google Patents

Abstract

The present invention relates to a pedestrian accident prevention control method using short-range portable mobile communication, and more particularly, by mounting two master antennas in a vehicle, the position is increased according to the driving direction of the vehicle, reception sensitivity with other devices, and an increase in antenna gain. By detecting the position and using the position information in the steering and braking control process of the vehicle to reduce the turning angle when turning the vehicle, the understeering tendency is shown, and the stopping distance is reduced by the braking control for the person or the vehicle recognized as the slave. The present invention relates to a pedestrian accident prevention control method using a near-field portable mobile communication to prevent accidents.

To this end, the present invention comprises the steps of repeating the inquiries and pairing (Inquiry / Pairing) process for a predetermined time to continuously search the peripheral devices (slave) by the communication between the vehicle using Bluetooth and Zigbee for a predetermined time; Mounting two masters in the vehicle by measuring the sensitivity of the receiving side and antenna gain in the above step, and accurately determining the position of other devices located at arbitrary points based on the in-vehicle distance; Forming a pairing process of exchanging a PIN (Product ID) with another device whose location is determined in the step, and determining whether the location of the other device is on the left / right side of the vehicle; Detecting a position according to a vehicle driving direction and an increase in reception sensitivity / antenna gain with another device, and reducing the turning angle and reducing the stopping distance through steering and braking control of the position information; It provides a pedestrian accident prevention control method using a near-portable mobile communication, characterized in that made.

Bluetooth / ZigBee, Master, Slave, Brake Pedal, ABS, Steering Motor

Description

Control method for prevention of pedestrian accident using the bluetooth and zigbee}

1 is a view for explaining the operation principle of the communication technology between the master-mounted vehicle and the peripheral device using Bluetooth and Zigbee,

FIG. 2 is a diagram illustrating a process of searching for a peripheral device using Bluetooth and ZigBee, and finding and accessing a device having a specific frequency.

3A and 3B are diagrams and a flowchart for explaining a distance measuring method with a conventional peripheral device using Bluetooth and ZigBee,

4 is a graph showing a change in distance between antennas according to a change in receiver sensitivity;

5 is a diagram illustrating an isotropic beam pattern and a beam pattern of an actual antenna for explaining antenna gain,

6 is a view for explaining a method for searching for a peripheral device of a vehicle equipped with two masters according to the present invention;

7A and 7B are diagrams for explaining a distance measurement between peripheral devices located at arbitrary points in a vehicle equipped with two masters according to the present invention;

8 is a schematic view showing an embodiment of the electric power steering apparatus according to the present invention,

9 is a schematic view showing an embodiment of a brake control apparatus according to the present invention;

10 is a flowchart illustrating a pedestrian accident prevention control method using a short-range portable mobile communication according to the present invention,

11 is a block diagram illustrating an embodiment of a RSSI-measurable Bluetooth module.

<Description of the symbols for the main parts of the drawings>

10: Master 11: Master / Slave

12 ~ 15: Slave 16: Master Cylinder

17 brake pedal 18 hydraulic control system

19: controller 20: ABS

21: wheel 22: steering motor

The present invention relates to a pedestrian accident prevention control method using short-range portable mobile communication, and more particularly, by mounting two master antennas in a vehicle, the position is increased according to the driving direction of the vehicle, reception sensitivity with other devices, and an increase in antenna gain. By detecting the position and using the position information in the steering and braking control process of the vehicle to reduce the turning angle when turning the vehicle, the understeering tendency is shown, and the stopping distance is reduced by the braking control for the person or the vehicle recognized as the slave. The present invention relates to a pedestrian accident prevention control method using a near-field portable mobile communication to prevent accidents.

As a pedestrian protection technology that detects pedestrians and prevents injuries, a system that reduces injuries from impacts by colliding pedestrians with accidents is being developed as a body shaping technology. ) Is expanding with increasing market and consumer needs.

As the post-collision injury reduction technology, a velocity measuring device and a hood raising system are disclosed in US Pat. No. 6,332,115, and an outboard airbag system is disclosed in US Pat. No. 6,880,666. Safety device for the protection of pedestrians is disclosed in US Pat. No. 4,249,632.

Due to the increased consumer awareness, a chassis control technology has been proposed that prevents pedestrian collisions by monitoring the frequency of communication in a portable mobile communication device, which is different from the conventional airbag operation after the design of the protection device.

Recently, technologies for detecting a vehicle in front of a vehicle using a Bluetooth / ZigBee device and an entry object, and detecting warnings of a peripheral communication device to add a warning and braking chassis steering assistance safety function to a driver are being developed.

The Bluetooth technology is a technology for wirelessly connecting communication between computers, peripheral devices, mobile phones, and PDAs in a short distance by short-range wireless communication without complicated wires, and currently, a collaboration between Ericsson, IBM, Nokia, Toshiba, etc. SIG) is enacting standard standards, and about 60 companies including Samsung Electronics, LG Electronics, and SK Telecom are participating in the SIG.

The Bluetooth is not only hardware, but also in the software part, and many SIG members are participating, and the biggest advantage is that the user's current needs can be immediately satisfied at a low price. At this time, the communication distance can be used up to 100m according to the class.

Practical Bluetooth technology is applied to a vehicle hands-free, and gradually improves communication between electronic products such as computer devices and PMPs in vehicles, and controls communication using discovery of short-range devices.

Zigbee, meanwhile, is a standard technology for automation and networks with a low transmission speed.It is possible to turn on / off the light control and security system VCR anywhere in the house with the push of a button at the touch of a button. It is a technology that enables home automation by dialing through the Internet.

In addition, the Zigbee is standardized in IEEE 802.15.4, the frequency band is 2.4GHz, 868 / 915MHz in dual PHY form, the modem method is a direct sequence spread spectrum (DS-SS), the data transmission rate is 20 to 250 kbps.

In addition, ZigBee is increasingly attracting attention as a wireless interface technology between a sensor and a device, and low-cost, low-power power communication technology enhances product competitiveness, and enables control using near field devices.

As the short-range wireless mobile communication technology, communication between vehicles and electronic products is increasing as a demand of customers, and new products that are newly developed are increasing in support of Bluetooth and Zigbee technologies.

The principle of operation of the Bluetooth and ZigBee technology is to find a peripheral device as shown in FIG. 1, establish a connection with the peripheral device after finding the peripheral device, confirm the connection, and provide a function (service). And releasing the connection.

Unexplained abbreviation LMP is a Link Management Protocol, and SDP is a Service Discovery Protocol.

That is, the Bluetooth and ZigBee technologies have a process of searching for a peripheral device as shown in FIG. 2 and finding and connecting a device having a specific frequency.

First of all, the standby state for waiting to participate in the PICONET (PICONET), the inquiries (INQUIRY) and the PAGE (PAGE) is connected to the active state to send the AMA (ACTIVE MEMBER ADDRESS).

The AMA is an address assigned to the slave by the master in the piconet and used to distinguish the slaves.

3A and 3B are diagrams and control flow diagrams for explaining the operation of Bluetooth and ZigBee technology, including: discovering a device between a master and a slave, matching a device between a master and a slave one-to-one, and matching the devices with each other. Connecting and communicating between the devices.

In this case, when the master discovers a slave device, a frequency gain is measured and relative distance information between the master and the slave is provided through the gain measurement.

However, with the current technology, as shown in the graph shown in FIG. 4, the distance from another device can be measured using the distance change between the antennas according to the change of the receiver (RX sensitivity), but the measurement of the angle is impossible.

FIG. 5 is a conceptual diagram illustrating an isotropic beam pattern and an actual antenna beam pattern. Antenna gain refers to a relative gain derived due to directivity as shown in Equation 1, and isotropic based on a maximum electric field direction. The ratio of the actual antenna radiation pattern to the radiation pattern.

That is, the signal is not increased due to the antenna, but the amount of energy (volume) of the isotropic radiation pattern and the actual antenna radiation pattern is the same, and thus the ratio of the energy when the energy to be spread evenly in all directions is concentrated in a certain direction. .

DB is used as the unit, and dBi is used when referring to an isotropic antenna, while dBd is also used when calculating gain based on a dipole antenna.

The higher gain of the antenna means that stronger electromagnetic waves can be sent in a specific direction in which electromagnetic waves are desired.

Many technologies for searching for peripheral devices and providing services through conventional short-range communication (Bluetooth, Zigbee, Wireless Lan) are being developed.

However, the distance between the master and the slave can be measured using the principle of the antenna by a method of finding a peripheral slave device from one communication master, but it is difficult to know the direction.

This is because the vehicle equipped with one master judges the positions of the vehicles and people at points a and b of FIG. 6 and the persons and vehicles at points c and d almost identically. Therefore, in order to measure the position accurately, it is necessary to measure distance using a plurality of sensors.

The present invention is conceived in view of the above, the vehicle is equipped with two master antennas to detect the position according to the vehicle driving direction, the reception sensitivity with other devices and the antenna gain increases, and the position information It can be used in steering and braking control of the vehicle to reduce the turning angle when turning the vehicle, to show understeer tendency, and to reduce the stopping distance through braking control to prevent accidents on people or vehicles recognized as slaves. An object of the present invention is to provide a pedestrian accident prevention control method using a short-range portable mobile communication.

In the present invention for achieving the above object in the pedestrian accident prevention control method using a short-range portable mobile communication,

Repeating an inquiry and pairing process for continuously searching for a peripheral device (slave) by communicating between vehicles using Bluetooth and Zigbee for a predetermined time; Mounting two masters in the vehicle by measuring the sensitivity of the receiving side and antenna gain in the above step, and accurately determining the position of other devices located at arbitrary points based on the in-vehicle distance; Forming a pairing process of exchanging a PIN (Product ID) with another device whose location is determined in the step, and determining whether the location of the other device is on the left / right side of the vehicle; Detecting a position according to a vehicle driving direction and an increase in reception sensitivity / antenna gain with another device, and reducing the turning angle and reducing the stopping distance through steering and braking control of the position information; Characterized in that made.

In a preferred embodiment, steering control of the vehicle may include detecting a slave through Bluetooth and ZigBee communication, determining driving conditions of the vehicle to determine whether the slave is in an accident possible path position, and the slave is in an accident And controlling the electric power steering (EPS) applied torque by receiving the slave protection signal when the path is in the possible path position.

In a more preferred embodiment, the braking control of the vehicle may include detecting a slave through Bluetooth and Zigbee communication, determining driving conditions of the vehicle to determine whether the slave is in an accident path position, and And controlling the brake braking torque by receiving the slave protection signal when the accident path is located.

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

6 is a view for explaining a method for searching for peripheral devices of a vehicle equipped with two masters according to the present invention.

The master / slave device 11 according to the present invention is a device that can alternately perform the functions of the master and the slave, and is used for network expansion (Piconet piconet, Scatternet scatternet), and the first time when switching from slave to master. Under the control of four.

The present invention can accurately locate the peripheral slave devices 12 to 15 from the two communication masters 10 and 11, and thus determine a dangerous situation by measuring the vehicle movement direction and the position of the peripheral slave devices.

In addition, when the direction lamp is operated, the output of one of the master 10 or the master / slave 11 can be relatively strengthened, so that it can be controlled to quickly find a device in a direction that matches the driver's will.

Mounting the two masters 10 and 11 in the vehicle has a difference from the existing technology.

By using the plurality of communication antennas to grasp the position information of the other communication device detected by the two antennas to ensure the vehicle safety by performing steering and braking control when a dangerous situation occurs in the vehicle driving direction and driving conditions.

7A and 7B are diagrams for explaining the distance measurement between the antennas of the two sides and the other communication device, the distance between point A and point B is a known distance in the vehicle, and any point C is the distance between point A and B. The angle can be inferred from the AC and BC linear information (antenna power reception sensitivity), and finally the distance from the vehicle can be obtained.

As shown in FIG. 7B,? ABC = 180 ° -β + γ

Sine law for each 사인 ABC is equal to Equation 2,

The distance between the actual A-B in the vehicle, a is given by Equation 3 below.

Therefore, the vertical distance h can be obtained from Equation 3 as shown in Equation 4 below.

According to the present invention, when the recognized slave is located between driving paths of the vehicle through the Bluetooth / ZigBee, the brake control system of the vehicle is operated to prevent collision with the slave device according to the speed approaching the vehicle.

The brake control system of the vehicle includes a master cylinder 16 for generating hydraulic pressure according to the pedal force of the brake pedal 17, a hydraulic control system 18 and a controller 19 for controlling the hydraulic pressure of the master cylinder 16, and hydraulic pressure. It is configured to include an ABS 20 connected to the control system 18 to control the wheel 21 brake of the vehicle.

The collision avoidance method between the master and the slave using the Bluetooth / ZigBee is as follows.

10 is a flowchart illustrating a pedestrian accident prevention control method using a short-range portable mobile communication according to the present invention.

1) Pairing the master (10, 11) and slaves (12-15) by searching for devices in the class (Inquiry) to connect the device ID and connected via Bluetooth / ZigBee. ) Enter the mode.

2) Measure the sensitivity of distance between master and slave.

In order to measure the reception strength of the Bluetooth / ZigBee for determining whether the communication is possible, distance sensitivity may be determined by measuring a received signal strength indicator (hereinafter referred to as RSSI) within a communication range.

The RSSI is a signal or a circuit indicating the strength of a signal flowing into a receiver, and a signal strength indicator of a mobile phone is a common example. The RSSI is often done in the IF stage before the IF amplifier.

On the other hand, in the 0-IF system, it is performed in the baseband signal chain in front of the baseband amplifier.

The RSSI output is often at the DC analog level. Sampling can be done by an internal ADC, and the result code is available directly or via a peripheral or via an internal process bus.

In the Bluetooth module, a control for adjusting the communication strength of RSSI is performed. When the standard class signal is received, the standard 20dBm specification can be confirmed.

Through the actual experiments, when the position of the vehicle is fixed, and the position of the AP and the output dBm information of the vehicle are acquired, rssi can be calculated from this and the distance can be indirectly measured.

Hereinafter, the control for adjusting the communication strength of the RSSI in the Bluetooth module will be described in detail.

11 is a block diagram illustrating an embodiment of an RSSI-measureable Bluetooth module, in which a receiver of an RF module monitors a RSSI (Received Signal Strength Indicator) in a Bluetooth communication, and sends an LMP (Link Management Protocol) control command from an RF transmitter. If the RSSI value is greater than the value needed for proper linking, this is done by the receiver requesting a reduction in transmit power.

If the RSSI value is too low, the receiver may request to increase the transmit power. The Bluetooth specification limits radiated power from 2dB to 8dB.

RSSI measurements, on the other hand, should be accurate from -60dBm to ± 4dB, starting at -60dB, with a minimum operating range of 20 ± 6dB. In practice, a Class 1 device monitors the RSSI and indirectly measures how far the receiver is from.

3) Measure the driving conditions of the vehicle.

4) Determine the possibility of collision between master and slave.

5) Activate brake to prevent collision between master and slave.

When the driving condition of the vehicle approaches the slave in a state where the slave recognized through the Bluetooth / ZigBee is detected, the motor assist torque Ta of the EPS (electric power steering) obtained by Equation 5 is lowered. More steering power is needed, resulting in a slight understeer tendency that differs from steering intent, preventing accidents on people / vehicles identified as slaves.

Where Θh: steering steering angle, Θs: steering steering angle, Th: operating torque, Ta: steering auxiliary torque, Tm: motor torque, Tre: reaction torque, Gear: gear reduction ratio, S: moving distance, Fs: moving shaft force, Ktsen: Torque sensor stiffness constant, Ctsen: torque sensor attenuation constant, Im: motor current, Tf: friction torque, J: steering inertia moment.

By changing the antenna gain during left / right blinking operation, it is equipped with logic that enhances the search in one direction so that the accuracy of the slave discovery and the distance to the master can be recognized more accurately, so this function can be used for vehicle steering / braking control conditions. .

The general principle of operation of the antenna is fixed in one direction, but two vehicle antennas acting as two masters can make the direction stronger.

For example, during a left turn (left flickering, steering angle left), the antenna gain of the left antenna B increases (the antenna gain of relative A decreases).

In the right turn (when the right blink operation is performed, the steering angle is left), the antenna gain of the right antenna A is increased (the antenna gain of the relative B is decreased).

Here, when the device is linked with the GPS, it is possible to more accurately find the location of the vehicle.

The collision detection method detects the location according to the driving direction of the vehicle, the reception sensitivity of the other device, and the increase of the antenna gain. By reducing the turning angle when turning the vehicle, it shows the tendency of understeer and reduces the stopping distance through braking control to prevent accidents on the person or vehicle recognized as a slave.

As described above, the communication means is limited to Bluetooth / ZigBee, but can be implemented by similar communication such as UWB (Ultra Wide Broadband), Wibro, CDMA.

While the invention has been shown and described with respect to certain preferred embodiments thereof, the invention is not limited to these embodiments, and has been claimed by those of ordinary skill in the art to which the invention pertains. It includes all the various forms of embodiments that can be carried out without departing from the spirit.

As described above, according to the pedestrian accident prevention control method using a short-range portable mobile communication according to the present invention, the position is detected according to the driving direction and the reception sensitivity and other antenna gain of the other device, and the position information It can be used for steering and braking control of the vehicle to reduce the turning angle when turning the vehicle, showing understeer tendency, and reducing the stopping distance through braking control to prevent accidents on people or vehicles recognized as slaves. have.

Claims (3)

In the pedestrian accident prevention control method using short-range portable mobile communication, Repeating an inquiry and pairing process for continuously searching for a peripheral device (slave) by communicating between vehicles using Bluetooth and Zigbee for a predetermined time; Determining the position of another device located at an arbitrary point based on the distance in the vehicle by mounting two masters in the vehicle by measuring the sensitivity of the receiving side and antenna gain in the above step; Forming a pairing process of exchanging a PIN (Product ID) with another device whose location is determined in the step, and determining whether the location of the other device is on the left / right side of the vehicle; It detects the location according to the driving direction of the vehicle and the increase in the reception sensitivity / antenna gain between other devices, and reduces the turning angle by using the location information between the vehicle and other devices in the vehicle steering and braking control process. Reducing; Pedestrian accident prevention control method using a near-portable mobile communication, characterized in that comprises a. The method according to claim 1, The steering control of the vehicle may include detecting a slave through Bluetooth and ZigBee communication, determining driving conditions of the vehicle to determine whether the slave is in an accident possible path position, and wherein the slave is in an accident possible path position. And controlling the electric power steering (EPS) applied torque in response to the slave protection signal being input in the case of the pedestrian accident prevention control method. The method according to claim 1 or 2, The braking control of the vehicle may include detecting a slave through Bluetooth and ZigBee communication, determining driving conditions of the vehicle to determine whether the slave is in an accident possible path position, and wherein the slave is in an accident possible path position. And controlling the brake braking torque by receiving a slave protection signal in the case of the pedestrian accident prevention control method.

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