KR102003727B1 - Apparatus for Preventing Drop Accident of Drone, and Method for Controlling the Same - Google Patents

Abstract

The present invention relates to a drone fall accident prevention device and a control method thereof, comprising: a drone fall accident prevention device detachable from a drone flying unmanned by a parachute compressed by an elastic means and accommodated in a container by an actuator; A parachute module including a parachute cover that is opened and closed; And a parachute control module configured to monitor the inclination and free fall of the drone to detect the fall of the drone and to control the actuator to open the parachute when the drone falls.

Description

Apparatus for Preventing Drop Accident of Drone, and Method for Controlling the Same}

The present invention relates to a fall accident prevention device, and more particularly, to a fall accident prevention device of a drone and a control method thereof.

'Drone' refers to an airplane or helicopter-shaped aircraft which is operated by radio wave guidance without humans. It is mainly used for military purposes such as target, reconnaissance, and surveillance. Is also used in a variety of applications.
In other words, drones are used for unmanned home delivery services in Internet shopping malls, such as photographing volcanic craters and places where people cannot go directly. In the case of unmanned courier services, documents, books, pizzas, etc. are delivered to individuals using GPS (satellite navigation) technology that uses satellites to determine the location.
In addition, recently, the use of drones has been gradually expanded, such as a helicam, which is equipped with a camera on a drone and remotely controls the drone to shoot an image, is widely used for broadcasting.
However, drones, despite many advantages, are also highly susceptible to falling due to changes in external environment such as wind and immaturity of driving operation. Since the drones and their parts are so expensive, the economic damage due to the damage of the drones is inevitably serious. In addition, if the drone falls, not only the enormous economic damage caused by the breakage of the drone itself, but also the risk of secondary damage to people and objects is serious.
Prior inventions include: Invention published in Japanese Patent Application Laid-Open No. 10-1496892 (March 3, 2015), invention disclosed in Japanese Patent Laid-Open No. 10-2016-0058561 (May 25, 2016), and Japanese Patent Application Laid-Open No. 2012-071645 ( Invention as published in 2012.04.12.

The present specification has been made to solve the above problems, and an object of the present invention is to provide a drone fall accident prevention device and a control method thereof that can prevent the fall of the drone when the drone is abnormal.

In order to achieve the above object, according to the first embodiment of the present specification, the fall accident prevention apparatus of the drone according to the present specification, in the fall accident prevention apparatus of the drone detachable to the drone flying unmanned, in the elastic means A parachute module including a parachute compressed by the parachute, and a parachute cover opened and closed by an actuator; And a parachute control module configured to monitor the inclination and free fall of the drone to detect the fall of the drone and to control the actuator to open the parachute when the drone falls.
The parachute control module may include: a gyro sensor measuring an angular velocity at which the drone rotates; An acceleration sensor measuring acceleration of the drone; And detecting the fall of the drone by monitoring the inclination and the free fall of the drone using the gyro sensor and the acceleration sensor, and controlling the actuator to open the parachute cover so that the parachute is unfolded when the drone falls. It characterized in that it comprises a control unit.
The controller initializes the gyro sensor and the acceleration sensor, calibrate the gyro sensor and the acceleration sensor to store offset values of the gyro sensor and the acceleration sensor, and uses the gyro sensor to drive the drone. It measures the angular velocity of, characterized in that it is determined that the drone falls if the X, Y value of the angular velocity measured by the gyro sensor is out of the predetermined range based on the stored offset value.
The control unit may determine that the drone falls when the X, Y value of the angular velocity> the stored offset value + 90 or the X, Y value of the angular velocity <the stored offset value-90.
The control unit may correct an error of the gyro sensor by applying the acceleration measured by the acceleration sensor to the angular velocity measured by the gyro sensor through a complementary filter.
The controller may determine that the drone falls when the drop of the drone lasts for more than 0.1 second at 8 meters per second or more.
The controller checks the battery capacity of the drone and warns of a low voltage of the battery when the capacity of the battery of the drone is less than 3.6 V, and limits the operation of the drone.
The parachute control module includes an air pressure sensor measuring an altitude of the drone; And a memory unit which stores a log including at least one of execution time, error type, and contents. The control unit may further include storing an error log together with the altitude measured by the barometric pressure sensor at the time when the parachute is deployed when the drone falls.
The controller checks whether there is an abnormality of the barometric pressure sensor after initializing the barometric pressure sensor.
The memory unit is a card type memory, and the controller checks whether the memory unit is inserted and capacity.
The controller may determine whether the gyro sensor and the acceleration sensor are abnormal after initializing the gyro sensor and the acceleration sensor.
According to a second embodiment of the present specification, the control method of the fall accident prevention apparatus of the drone according to the present specification, in the control method of the fall accident prevention apparatus of the drone detachable to the drone flying unmanned, gyro sensor and acceleration sensor Detecting a fall of the drone by monitoring a tilt and a free fall of the drone using; And a parachute module compressed by an elastic means and accommodated in a container when the drone falls, wherein the parachute module is opened and closed by an actuator, the parachute module being configured to control the actuator to open the parachute to open the parachute cover. Steps.
Initializing the gyro sensor and the acceleration sensor before detecting the fall of the drone; And calibrating the gyro sensor and the acceleration sensor to store offset values of the gyro sensor and the acceleration sensor.
The detecting of the fall of the drone may include: measuring an angular velocity of the drone using the gyro sensor; And determining that the drone falls when the X and Y values of the angular velocity measured by the gyro sensor are out of a predetermined range based on the stored offset value.
In the step of determining that the drone is falling, when the X, Y value of the angular velocity> the stored offset value + 90 or the X, Y value of the angular velocity <stored offset value-90, characterized in that it is determined that the drone falls. .
Detecting the fall of the drone, between measuring the angular velocity of the drone and determining that the drone is falling, the acceleration to the angular velocity measured by the gyro sensor through a compensation filter (Complementary Filter) The method may further include correcting an error of the gyro sensor by applying the acceleration measured by the sensor.
In the step of detecting the fall of the drone, if the fall of the drone lasts for more than 0.1 seconds at 8 meters per second or more characterized in that it is determined that the drone falls.
The control method of the fall accident prevention apparatus of the drone, characterized in that further comprising the step of checking the abnormality of the gyro sensor and the acceleration sensor.
The control method of the fall accident prevention apparatus of the drone, before the step of detecting the fall of the drone, checking the battery capacity of the drone; And warning a low voltage of the battery when the capacity per cell of the battery of the drone is less than 3.6 V, and limiting the operation of the drone.
The parachute control module further includes a barometric pressure sensor for measuring the altitude of the drone, and the method of controlling the fall accident prevention device of the drone is measured by the barometric pressure sensor when the parachute is unfolded when the drone falls. And storing an error log including at least one of an execution time, an error type, and a content together with the altitude.
The control method of the fall accident prevention device of the drone, characterized in that it further comprises the step of flashing the LED when the fall of the drone, and reproducing the error sound.

As described above, according to the present specification, by providing a drone fall accident prevention device and a control method thereof, which detects the fall of the drone and expands the parachute when the drone falls, the damage caused by the fall of the drone can be prevented. It can greatly reduce the physical and property damage of others.

1 is a perspective view of a drone equipped with an accident prevention apparatus according to an embodiment of the present invention;
2 is a view for explaining the operation method of the parachute control module according to an embodiment of the present invention,
Figure 3 is a block diagram showing a schematic configuration of the interior of the parachute control module according to an embodiment of the present invention,
4 is a flow chart showing a control method of the fall accident prevention device of the drone before the flight according to an embodiment of the present invention, and
5 and 6 are flowcharts showing a control method of the fall accident prevention device of the drone during the flight according to an embodiment of the present invention.

It is to be noted that the technical terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. In addition, the technical terms used in the present specification should be interpreted as meanings generally understood by those skilled in the art unless they are specifically defined in this specification, and are overly inclusive. It should not be interpreted in the sense of or in the sense of being excessively reduced. In addition, when the technical terms used herein are incorrect technical terms that do not accurately represent the spirit of the present invention, it should be replaced with technical terms that can be understood correctly by those skilled in the art. In addition, the general terms used in the present invention should be interpreted as defined in the dictionary or according to the context before and after, and should not be interpreted in an excessively reduced sense.
Also, the singular forms used herein include the plural forms unless the context clearly indicates otherwise. In the present application, terms such as “consisting of” or “comprising” should not be construed as necessarily including all of the various components, or various steps described in the specification, wherein some of the components or some of the steps It should be construed that it may not be included or may further include additional components or steps.
In addition, the suffixes "module" and "unit" for the components used herein are given or mixed in consideration of ease of specification, and do not have meanings or roles that are distinguished from each other.
In addition, terms including ordinal numbers, such as first and second, as used herein may be used to describe various components, but the components should not be limited by the terms. The terms are used only for the purpose of distinguishing one component from another. For example, without departing from the scope of the present invention, the first component may be referred to as the second component, and similarly, the second component may also be referred to as the first component.
Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings, and the same or similar components will be given the same reference numerals regardless of the reference numerals, and redundant description thereof will be omitted.
In addition, in describing the present invention, when it is determined that the detailed description of the related known technology may obscure the gist of the present invention, the detailed description thereof will be omitted. In addition, it is to be noted that the accompanying drawings are only for easily understanding the spirit of the present invention and are not to be construed as limiting the spirit of the present invention by the accompanying drawings.
1 is a perspective view of a drone equipped with a fall accident prevention apparatus according to an embodiment of the present invention.
First, the drone 100 will be manually operated by the ground manager or automatically controlled by a set flight program. Such a drone 100 is composed of a configuration including a main frame 110, a horizontal and vertical moving propulsion device 120, and a landing leg 130, as shown in FIG.
The main frame 110 is a body portion on which a module such as a camera module (200 of FIG. 2) is mounted.
The horizontal and vertical movement propulsion device 120 is composed of one or more propellers 122 installed perpendicular to the main frame 110, the horizontal and vertical movement propulsion device 120 according to an embodiment of the present invention is spaced apart from each other It consists of a plurality of propellers 122. In this case, the horizontal and vertical moving propulsion device 120 may be formed of an air injection type propeller instead of a propeller.
Landing legs 130 are spaced apart from each other on the bottom surface of the main frame (110). In addition, a lower portion of the landing leg 130 may be equipped with a buffer support member 132 for minimizing the impact caused by the collision with the ground when the drone 100 lands.
Of course, the drone 100 may be made of a variety of structures of different aircraft configuration.
On the other hand, the fall accident prevention apparatus 300 according to the present invention is mounted between the pair of landing legs 130 by using the fixing means 330, but is not limited thereto, and affects the flight of the drone 100. It may be mounted on the top or bottom of the main frame 110 in a line not given.
Fall accident prevention device 300 is largely composed of a parachute module 310 and the parachute control module 320.
The parachute module 310 includes a parachute 313 compressed by a spring 311 which is an elastic means and accommodated in the container 312, and is configured to allow the parachute 313 to be unfolded by the actuator 314.
1 and 2, the parachute module 310 includes a support 311a together with a spring 311 and a parachute 313, and the spring 311 is compressed by the parachute cover 315. Then, when the locking means 314a is released by the operation of the actuator 314, the parachute cover 315 is opened so that the spring 311 is elastically restored and the compressed state is released and the parachute 313 is unfolded.
For example, as shown in FIG. 2A, when the actuator 314 is located at about 90 °, the locking means 314a is locked. As shown in FIG. 2B, when the actuator 314 is located at about 170 °, the locking means 314a is released, and the parachute cover 315 is opened to unfold the parachute 313.
The parachute control module 320 detects the fall of the drone 100 by monitoring the inclination and the free fall of the drone 100, and controls the actuator 314 to expand the parachute 313 when the drone 100 falls. The parachute cover 315 is opened. To this end, the parachute control module 320 according to the present invention may include various sensors such as a gyro sensor, an acceleration sensor, and an air pressure sensor, a controller, a GPS receiver, a communication module, and a memory unit. Detailed configuration of the parachute control module 320 will be described below.
Figure 3 is a block diagram showing a schematic configuration of the interior of the parachute control module according to an embodiment of the present invention.
First, prior to the description, the drone 100 measures its own flight state using various sensors in order to fly stably. The drone's flight state is defined as a rotational state and a translational state. Rotational motion state means 'Yaw', 'Pitch' and 'Roll', and translational motion state means longitude, latitude, altitude, and speed.
Here, 'roll', 'pitch', and 'yo' are called Euler angles, where the three axes x, y, z of the aircraft's aircraft coordinates are some specific coordinates, e.g., NED coordinates N, E, D three. Represents an angle rotated about an axis. If the front of the plane rotates left and right with respect to the z-axis of the aircraft coordinates, the x-axis of the aircraft coordinates will have an angular difference with respect to the N-axis of the NED coordinates, which is called "yaw" (Ψ). If the front of the plane rotates up and down with respect to the y-axis toward the right, the z-axis of the aircraft coordinates will have an angle difference with respect to the D-axis of the NED coordinate, and this angle is called "pitch" (θ). If the aircraft's fuselage is tilted left and right with respect to the front x-axis, the y-axis of the aircraft coordinates will be angled with respect to the E-axis of the NED coordinates, which is referred to as "roll" (Φ).
The drone 100 uses three-axis gyroscopes, three-axis accelerometers, and three-axis magnetometers to measure rotational motion, and a GPS receiver to measure translational motion. A barometric pressure sensor is used.
In order to monitor the motion state of the drone 100, the parachute control module 320 according to the present invention includes a gyro sensor 31, an acceleration sensor 32, and a barometric pressure sensor 33. Here, the gyro sensor 31 and the acceleration sensor 32 measure the state in which the body frame coordinate of the drone 100 is rotated with respect to the earth centered inertial coordinate and the accelerated state. Micro-Electro-Mechanical Systems Using semiconductor process technology, it can also be fabricated as a single chip called an Inertial Measurement Unit (IMU). In addition, inside the IMU chip, measurements of the geo-inertia coordinates measured by the gyro sensor 31 and the acceleration sensor 32 are local coordinates, for example, North-East-Down (NED) coordinates used by GPS. Microcontrollers can be included to convert the In addition, the parachute control module 320 may further include a control unit 34, a memory unit 35, an LED unit 36, and an alarm unit 37.
The gyro sensor 31 measures the angular velocity at which three axes x, y, and z of the drone 100 rotate about the earth's inertial coordinate, and then converts the values into fixed coordinates (Wx.gyro, Wy.gyro, and Wz. gyro) and convert it to Euler angles (Φgyro, θgyro, ψgyro) using a linear differential equation. Here, since the measurement of the gyro sensor 31 includes a bias error in the low frequency band (that is, the measurement of the gyro sensor does not become zero even when the drone is stopped), the three axes of x, y, and z The bias error of the gyro sensor 31 should be eliminated. The method for this will be described later.
The acceleration sensor 32 measures the acceleration of the drone 100 with respect to geocoordinates of three axes x, y and z and then converts the values (fx, acc, fy, acc, fz, acc) into fixed coordinates. Calculate and convert these values into Φacc and θacc, which are calculated using the gyro sensor 31's Φgyro and gygy. It is used to eliminate the bias error included in the. However, since the acceleration sensor 32 cannot measure the yaw, the bias error included in the yaw measured by the gyro sensor 31 cannot be removed. To this end, the parachute control module 320 according to the present invention may further include a geomagnetic sensor (not shown).
The geomagnetic sensor (not shown) measures the direction of the magnetic north point of the gas coordinates x, y, and z of the drone 100, and calculates the 'yaw' value of the NED coordinates of the gas coordinates using this value. The controller 34 removes a bias error included in the measured value 'gygyro' of the gyro sensor 31 using 'yo' measured by a geomagnetic sensor (not shown).
The GPS receiver (not shown) uses the signals received from the GPS satellites to translate the drone 100 on the NED coordinates, ie latitude (Pn.GPS), longitude (Pe.GPS), altitude (hMSL.GPS). , Velocity on latitude (Vn.GPS), velocity on longitude (Ve.GPS), and velocity on altitude (Vd.GPS) are calculated. Here, the subscript MSL means sea level (MSL).
There is always an error of 5 to 10 m in position coordinates received through a GPS receiver (not shown). The civil GPS receiver can receive only one of C / A (Coarse-Acquisition) codes of the L1 frequency band (1.5 kHz) or C / A codes of the L2 frequency band (1.2 kHz). However, military GPS receivers can receive L1 C / A and L2 C / A at the same time, gaining diversity, and additionally receiving an encrypted signal P (Y). Disturbance can be corrected when the GPS signal passes through the earth's ion layer (Ionospheric Correction). GPS altitude errors of 5 m to 10 m create a risk of collisions with low-flying drone ground facilities. Therefore, the altitude (hALP.baro) may be measured using a separate barometric pressure sensor. Here, the subscript ALP means air pressure (Air-Level Pressor), and the air pressure sensor 33 calculates a current altitude from the takeoff point by comparing the air pressure at takeoff of the drone 100 with the air pressure at the current flight altitude.
The controller 34 may easily update the firmware, use open source, and apply Arduino, which has recently been spotlighted on the IoT. The controller 34 detects the fall of the drone 100 by monitoring the inclination and free fall of the drone 100 using the gyro sensor 31 and the acceleration sensor 32, and when the drone 100 falls, a parachute ( Actuator 314 is controlled to unfold 313 to open parachute cover 315. Hereinafter, a detailed method of controlling the parachute module 310 by the controller 34 will be described.
First, the control unit 34 initializes each component constituting the parachute control module 32 prior to the control of the parachute module 310.
That is, the controller 34 turns on the green LED through the LED unit 36 when power is applied and checks the battery capacity of the drone 100. The controller 34 warns of the low voltage of the battery when the capacity per cell of the battery is less than 3.6V. That is, the control unit 34 flashes the green LED and the red LED through the LED unit 36, reproduces the error sound through the alarm unit 37, and an error log including an execution time, an error type, and contents thereof. Is stored in the memory unit 35. In this case, the controller 34 may limit the operation of the drone 100 when the capacity of the battery is low voltage.
The controller 34 initializes the gyro sensor 31, the acceleration sensor 32, and the barometric pressure sensor 33, checks whether there is an abnormality of each sensor, and calibrates the gyro sensor 31 and the acceleration sensor 32. It stores the offset values of the gyro sensor 31 and the acceleration sensor 32. Here, the controller 34 flashes the yellow LED through the LED unit 36 during initialization and calibration, and if there is an abnormality in any sensor, the green LED and the yellow LED flash through the LED unit 36, and the alarm unit An error sound is reproduced through 37, and an error log including execution time, error type, contents, and the like is stored in the memory unit 35.
In addition, the controller 34 initializes the memory unit 35, checks the capacity of the memory unit 35, and if the free space is less than 10 megabytes, the yellow LED and the red LED blink through the LED unit 36. The error sound is reproduced through the alarm unit 37. At this time, the controller 34 allows the drone 100 to operate, but disables the black box function for storing an error log and a flight log. In addition, when the memory unit 35 is a card type memory, the controller 34 may check whether the memory is inserted.
The control unit 34 also initializes the actuator 314. That is, the control unit 34 closes the parachute cover 315 by placing the actuator 314 at 90 °. As described above, the controller 34 completes the initialization of the gyro sensor 31, the acceleration sensor 32, the barometric pressure sensor 33, the memory unit 35, and the actuator 314, and then the LED unit 36. By turning off the yellow LED and playing the completion sound, the user is notified that the initialization is complete.
Meanwhile, when the drone 100 starts to fly after a series of initialization processes are completed, the control unit 34 detects the fall of the drone 100 and the actuator to expand the parachute 313 when the drone 100 falls. 314 is controlled to open the parachute cover 315. Here, the method of detecting the fall of the drone 100 by the controller 34 may be divided into two methods as follows.
First, the controller 34 may monitor the fall of the drone 100 by monitoring the inclination of the drone 100. Specifically, the controller 34 measures the angular velocity of the drone 100 using the gyro sensor 31, and the X and Y values of the angular velocity measured by the gyro sensor 31 store the offset values stored in the initialization process. If the reference value is out of the preset range (for example, when the X and Y values of the angular velocity are greater than +90 or less than -90 than the stored offset value), the drone 100 is determined to fall.
In this case, the controller 34 may correct the error of the gyro sensor 32 by applying the acceleration measured by the acceleration sensor 32 to the angular velocity measured by the gyro sensor 31 through a complementary filter. have. Specifically, the compensation filter extracts the state measurements Φgyro and θgyro of the gyro sensor 31 having good high frequency band characteristics with the high frequency band filter, and measures the state measurements Φacc and θacc of the acceleration sensor 32 having good low frequency band characteristics. ) Is extracted with the low frequency filter, and the two are combined to calculate the state estimates ΦE and θE in which the bias error of the gyro sensor 31 is minimized.
In addition, the controller 34 according to the present invention may correct the error of the angular velocity measured by the gyro sensor 31 using an extended Kalman filter. Specifically, the extended Kalman filter includes measured values (Φgyro, θgyro, ψgyro) using the gyro sensor 31, measured values (Φacc, θacc) using the acceleration sensor 32, measured values (ψmag) using a geomagnetic sensor (not shown). And a gyro sensor 31 and an acceleration sensor while modeling rotational dynamics of the drone 100 in real time using measurements (Vn.GPS, Ve.GPS, Vd.GPS) using a GPS receiver (not shown). The state estimates ΦE, θE, and ψE in which the bias error of (32) is minimized are calculated. To this end, the parachute control module 320 according to the present invention preferably includes the above-described geomagnetic sensor (not shown) and GPS receiver (not shown).
Secondly, the controller 34 may detect the fall of the drone 100 by monitoring the free fall of the drone 100. Specifically, the controller 34 determines that the drone 100 falls when the fall of the drone 100 lasts for more than 0.1 second per second or more by using the gyro sensor 31 and the acceleration sensor 32. do. This is because the range in which the drone 100 operates normally is 0 to 6 meters per second.
The memory unit 35 stores a log including execution time, error type, contents, and the like. The memory unit 35 may include a flash memory type, a hard disk type, a multimedia card micro type, a card type memory (for example, SD or XD memory), It may include a storage medium of at least one type of RAM and ROM. In this case, when the memory unit 35 is a card type memory, the parachute control module 320 according to the present invention may include a memory slot instead of the memory unit 35.
The LED unit 36 may include a green LED, a red LED, and a yellow LED. The LED unit 36 may display whether or not the battery is low voltage, whether each sensor is abnormal, the initialization and calibration progress state, the capacity state of the memory unit 35, whether the initialization is completed, and whether the drone 100 has fallen.
The alarm unit 37 together with the LED unit 36 indicates whether the battery is low voltage, whether each sensor is abnormal, the initialization and calibration progress state, the capacity state of the memory unit 35, whether the initialization is completed, and whether the drone 100 falls down. Outputs a signal to inform the back. The alarm unit 37 outputs a signal for notifying occurrence of an event in a form other than an audio signal or a video signal. For example, the signal can be output in the form of sound or vibration.
Figure 4 is a flow chart showing a control method of the fall accident prevention device of the drone before the flight according to an embodiment of the present invention.
Referring to FIG. 4, the parachute control module 320 checks the battery capacity of the drone 100 to determine whether the battery capacity of the drone 100 is 3.6 V or more (S410). In this case, the battery capacity means capacity per cell of the battery.
The parachute control module 320 warns the battery low voltage when the battery capacity of the drone 100 is less than 3.6 V (S412). For example, the parachute control module 320 blinks a green LED and a red LED through the LED unit 36, reproduces an error sound through the alarm unit 37, and displays execution time, error type, and contents. An error log may be stored in the memory unit 35. In this case, the parachute control module 320 may limit the operation of the drone 100.
If the battery capacity of the drone 100 is 3.6 V or more, the parachute control module 320 initializes the gyro sensor 31 and the acceleration sensor 32 (S420), and initializes the barometric pressure sensor 33 (S430). In operation S450, it is determined whether or not there is an abnormality in each sensor.
If the parachute control module 320 has an abnormality in any sensor, the parachute control module 320 warns a sensor abnormality (S452). For example, the parachute control module 320 blinks a green LED and a yellow LED through the LED unit 36, reproduces an error sound through the alarm unit 37, and displays execution time, error type, and contents. The included error log is stored in the memory unit 35.
If the parachute control module 320 has no abnormality in the sensor, the gyro sensor 31 and the acceleration sensor 32 are calibrated (S460), and the offset values of the gyro sensor 31 and the acceleration sensor 32 are stored in the memory unit ( 35) (S470).
In addition, the parachute control module 320 initializes the memory unit 35 at the same time as the steps S420 and S430 (S440) and checks the capacity of the memory unit 35 so that the free space of the memory unit 35 is 10 megabytes. It is determined whether or not (S442). In this case, the parachute control module 320 may check whether the memory is inserted when the memory unit 35 is a card type memory.
The parachute control module 320 warns of insufficient memory when the free space of the memory unit 35 is 10 megabytes or less (S444). For example, the parachute control module 320 blinks a yellow LED and a red LED through the LED unit 36, and reproduces an error sound through the alarm unit 37. At this time, the parachute control module 320 allows the drone 100 to operate, but disables the black box function for storing an error log and a flight log.
The parachute control module 320 initializes the actuator 314 after steps S470 and S442 (S480). For example, the parachute control module 320 closes the parachute cover 315 with the actuator 314 positioned at 90 °.
In addition, the parachute control module 320 completes the initialization of the gyro sensor 31, the acceleration sensor 32, the barometric pressure sensor 33, the memory unit 35, and the actuator 314, and then the LED unit 36. By turning off the yellow LED and playing the completion sound, you can inform the user that the initialization is complete.
Meanwhile, in the exemplary embodiment of the present invention, for convenience of description, steps S420, S430, and S440 are simultaneously performed, but the present invention is not limited thereto, and steps S420, S430, and S440 may be sequentially performed. For example, step S420, step S450, step S460, step S470, step S430, step S450, step S440, step S442, and step S480 may be performed in order.
5 and 6 are flowcharts showing a control method of the fall accident prevention device of the drone during the flight according to an embodiment of the present invention.
The parachute control module 320 according to the present invention detects the fall of the drone 100 by monitoring the inclination of the drone 100 as shown in FIG. 5, or frees the drone 100 as shown in FIG. 6. The fall may be monitored to detect the fall of the drone 100.
First, referring to FIG. 5, the parachute control module 320 reads the sensor values of the gyro sensor 31 and the acceleration sensor 32 (S510). That is, the parachute control module 320 measures the angular velocity of the drone 100 using the gyro sensor 31 and measures the acceleration of the drone 100 using the acceleration sensor 32.
The parachute control module 320 corrects an error of the gyro sensor 32 by applying the acceleration measured by the acceleration sensor 32 to the angular velocity measured by the gyro sensor 31 through the compensation filter (S520). Specifically, the compensation filter extracts the state measurements Φgyro and θgyro of the gyro sensor 31 having good high frequency band characteristics with the high frequency band filter, and measures the state measurements Φacc and θacc of the acceleration sensor 32 having good low frequency band characteristics. ) Is extracted with the low frequency filter, and the two are combined to calculate the state estimates ΦE and θE in which the bias error of the gyro sensor 31 is minimized.
In addition, the parachute control module 320 may correct the error of the angular velocity measured by the gyro sensor 31 using the extended Kalman filter in step S520. Specifically, the extended Kalman filter includes measured values (Φgyro, θgyro, ψgyro) using the gyro sensor 31, measured values (Φacc, θacc) using the acceleration sensor 32, measured values (ψmag) using a geomagnetic sensor (not shown). And a gyro sensor 31 and an acceleration sensor while modeling rotational dynamics of the drone 100 in real time using measurements (Vn.GPS, Ve.GPS, Vd.GPS) using a GPS receiver (not shown). The state estimates ΦE, θE, and ψE in which the bias error of (32) is minimized are calculated.
Subsequently, the parachute control module 320 determines whether the X and Y values of the angular velocity measured by the gyro sensor 31 are out of a preset range based on the offset values stored in the initialization process (S530). If the X and Y values of the angular velocity measured by (31) do not deviate from the preset range based on the stored offset value, the process returns to step S510.
When the parachute control module 320 is out of a preset range based on the stored offset value, the X and Y values of the angular velocity measured by the gyro sensor 31 are stored. If greater than +90 or less than -90), the drone 100 is determined to fall, and the actuator 314 is controlled to open the parachute 313 to open the parachute cover 315 (S540). That is, the parachute control module 320 rotates the actuator 314 from about 90 ° to about 170 °, releases the locking means 314a, and opens the parachute cover 315 to open the parachute 313. At this time, the parachute control module 320 blinks a red LED through the LED unit 36, reproduces a 90-degree tilting error sound through the alarm unit 37, and includes execution time, error type, and contents. The error log may be stored in the memory unit 35.
Meanwhile, referring to FIG. 6, the parachute control module 320 monitors free fall of the drone 100 by using the gyro sensor 31 and the acceleration sensor 32 (S610).
The parachute control module 320 determines whether the fall of the drone 100 lasts for at least 0.1 second at 8 meters per second or more (S620). In general, the range in which the drone 100 operates normally is 0 to 6 meters per second, except for the range in which the drone 100 operates normally, the initial speed and time for determining the free fall may be changed by the user. Of course.
The parachute control module 320 determines that the drone 100 falls when the drone 100 falls free, and controls the actuator 314 to open the parachute 313 to open the parachute cover 315 ( S630). That is, the parachute control module 320 rotates the actuator 314 from about 90 ° to about 170 °, releases the locking means 314a, and opens the parachute cover 315 to open the parachute 313. At this time, the parachute control module 320 blinks a yellow LED through the LED unit 36, reproduces a free fall error sound through the alarm unit 37, and errors including execution time, error type, and contents. The log may be stored in the memory unit 35.
The aforementioned method can be implemented through various means. For example, embodiments of the present invention may be implemented by hardware, firmware, software, or a combination thereof.
For implementation in hardware, a method according to embodiments of the present invention may include one or more Application Specific Integrated Circuits (ASICs), Digital Signal Processors (DSPs), Digital Signal Processing Devices (DSPDs), and Programmable Logic Devices (PLDs). And field programmable gate arrays (FPGAs), processors, controllers, microcontrollers and microprocessors.
In the case of an implementation by firmware or software, the method according to the embodiments of the present invention may be implemented in the form of a module, a procedure, or a function that performs the functions or operations described above. The software code may be stored in a memory unit and driven by a processor. The memory unit may be located inside or outside the processor, and may exchange data with the processor by various known means.
Thus, in the embodiment of the present invention, by providing a drone fall accident prevention device and a control method for detecting the fall of the drone, the parachute unfolds when the drone falls, it is possible to prevent the damage caused by the fall of the drone This can dramatically reduce the physical and property damage of others.
Embodiments disclosed herein have been described with reference to the accompanying drawings. As described above, the embodiments shown in each drawing should not be construed as limiting, but may be combined with each other by those skilled in the art, and some components may be omitted.
Here, the terms or words used in the present specification and claims should not be construed as being limited to the ordinary or dictionary meanings, but should be interpreted as meanings and concepts corresponding to the technical spirit disclosed in the present specification.
Therefore, the embodiments described in the present specification and the configuration shown in the drawings are merely exemplary embodiments disclosed herein, and do not represent all of the technical ideas disclosed in the present specification, and various equivalents may be substituted for them at the time of the present application. It should be understood that there may be water and variations.

However, drones, despite many advantages, are also highly susceptible to falling due to changes in external environment such as wind and immaturity of driving operation. Since the drones and their parts are so expensive, the economic damage due to the damage of the drones is inevitably serious. In addition, if the drone falls, not only the enormous economic damage caused by the breakage of the drone itself, but also the risk of secondary damage to people and objects is serious.
Prior inventions include: Invention published in Japanese Patent Application Laid-Open No. 10-1496892 (March 3, 2015), invention disclosed in Japanese Patent Laid-Open No. 10-2016-0058561 (May 25, 2016), and Japanese Patent Application Laid-Open No. 2012-071645 ( Invention as published in 2012.04.12.

100: drone 110: main frame
120: horizontal and vertical movement propulsion device 122: propeller
130: landing leg 132: buffer support member
200: camera 300: fall accident prevention device
310: parachute module 311: spring
311a: support 312: container
313: parachute 314: actuator
314a: locking means 315: parachute cover
320: parachute control module 330: fixing means
31: gyro sensor 32: acceleration sensor
33: barometric pressure sensor 34: control unit
35: memory unit 36: LED unit
37: alarm unit

Claims (14)

In the fall accident prevention device of the drone detachable to the drone flying unmanned,
A parachute module including a parachute cover opened and closed by an actuator, elastic means compressed by the parachute cover accommodated together in a container, and a parachute; And
Detect the fall of the drone by monitoring the tilt and free fall of the drone,
A parachute control module that opens the parachute cover by controlling the actuator to expand the parachute when the drone falls;
Including,
The parachute control module,
A gyro sensor measuring an angular velocity at which the drone rotates;
An acceleration sensor measuring acceleration of the drone;
A geomagnetic sensor that measures a direction of the drone's magnetic north point;
An air pressure sensor measuring an altitude of the drone;
A GPS receiver for measuring the position of the drone;
A memory unit for storing a log including at least one of execution time, error type, and contents;
By monitoring the inclination and free fall of the drone by using the gyro sensor, the acceleration sensor and the geomagnetic sensor, the fall of the drone is sensed, and the parachute cover by controlling the actuator to expand the parachute when the drone falls A control unit for opening the;
An alarm unit for outputting a signal for notifying when the controller detects the fall of the drone;
Including,
The control unit initializes the gyro sensor, the acceleration sensor, the barometric pressure sensor, and confirms whether there is an abnormality of each sensor,
The controller is configured to calibrate the gyro sensor and the acceleration sensor to store offset values of the gyro sensor and the acceleration sensor,
The controller uses the extended Kalman filter to measure the angular velocity measured by the gyro sensor, the acceleration measured by the acceleration sensor, the measured value using the geomagnetic sensor, and the measured value using the GPS receiver. To calibrate,
The controller stores an error log together with the altitude measured by the barometric pressure sensor at the time when the parachute is deployed when the drone falls,
The control unit is based on the offset value stored in the X, Y value of the angular velocity corrected by the extended Kalman filter based on the X, Y value of the angular velocity> the stored offset value + 90 or the X, Y value of the angular velocity < If the drone falls within the range of the stored offset value -90, it is determined that the drone falls.
The controller of claim 1, wherein the drone falls, if the fall of the drone lasts for more than 0.1 seconds at 8 meters per second or more.
delete delete delete delete delete The method of claim 1,
The controller checks the battery capacity of the drone, if the cell capacity of the battery of the drone is less than 3.6V warning the low voltage of the battery, the drone fall accident prevention device, characterized in that to limit the operation of the drone.
delete delete The method of claim 1,
The memory unit is a card type memory,
The control unit is a fall accident prevention device of the drone, characterized in that for checking the insertion and capacity of the memory unit.
delete In the control method of the fall accident prevention device of the drone detachable to the drone flying unmanned,
Checking battery capacity of the drone;
Warning the low voltage of the battery and limiting the operation of the drone when the capacity per cell of the battery of the drone is less than 3.6 V;
Initializing a gyro sensor, an acceleration sensor, and a barometric pressure sensor;
Confirming an abnormality of the gyro sensor, the acceleration sensor, and the barometric pressure sensor;
Calibrating the gyro sensor and the acceleration sensor to store offset values of the gyro sensor and the acceleration sensor;
Detecting the fall of the drone by monitoring the inclination and the free fall of the drone using the gyro sensor and the acceleration sensor;
A parachute module including a parachute cover opened and closed by an actuator when the drone falls, an elastic means and a parachute compressed by the parachute cover housed together in a container, wherein the actuator is controlled so that the parachute is unfolded. Opening the cover;
Storing an error log including at least one of an execution time, an error type, and contents together with an altitude measured by an air pressure sensor at the time when the parachute is deployed when the drone falls; And
Flashing an LED when the drone falls and reproducing an error sound;
Including,
Detecting the fall of the drone,
Measuring the angular velocity of the drone using the gyro sensor;
Specifying the speed and acceleration of the drone via a GPS receiver;
Measuring a direction of the drone's magnetic north point through a geomagnetic sensor;
Correcting an error of the gyro sensor through an angular velocity measured by the gyro sensor, an acceleration measured by the acceleration sensor, a measured value using the geomagnetic sensor, and a measured value using a GPS receiver through an extended Kalman filter; And
And determining that the drone falls when the X and Y values of the angular velocity measured by the gyro sensor are out of a preset range based on the stored offset value.
The step of determining that the drone is falling,
Determining that the drone falls when the X, Y value of the angular velocity> the stored offset value + 90 or the X, Y value of the angular velocity <the stored offset value-90;
And determining that the drone falls if at least one of the cases in which the fall of the drone lasts for more than 0.1 second per second at 8 meters per second or more is included.

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