JP6235213B2 - Autonomous flying robot - Google Patents

Description

  The present invention relates to an autonomous flight robot that autonomously flies so that the self position can be estimated even when the self position cannot be estimated.

  2. Description of the Related Art Conventionally, an autonomous mobile robot that can move autonomously based on map information stored in advance and sensor information from various sensors included in the device has been proposed. For example, in Patent Document 1, distance information from an obstacle around an autonomous mobile robot is measured using a distance detection sensor such as a laser range finder, and map information including obstacles such as buildings stored in advance (obstacles) An autonomous mobile robot that can autonomously move by estimating a self-position in a moving space using a map) and an output value (distance data) of a distance detection sensor is disclosed.

JP 2012-137909 A

  When using the method of estimating the self-position using the distance detection sensor as in the above prior art, for example, when the obstacle installation environment greatly changes due to the appearance of a large obstacle such as a truck, Since the stored obstacle map and the actual obstacle layout are greatly deviated, the self-location may not be estimated appropriately. However, the above-described conventional technology does not consider the case where such a self-position cannot be estimated, and therefore cannot appropriately move autonomously when the self-position cannot be estimated. By the way, in recent years, from the aspect of being able to move freely in space without being restricted by obstacles such as objects and steps on the moving path, it is possible to move to a position where it is difficult to be attacked by intruders, etc. The use of autonomous flying robots, such as autonomously moving a flying robot to monitor an intruder, has been studied. In such an autonomous flight robot, when autonomous flight becomes difficult, not only is it easy to be attacked by an intruder, but there is also a possibility of causing an accident due to a collision with a building or a person or a crash. Accordingly, an object of the present invention is to enable an autonomous flight robot to stably fly autonomously by performing autonomous flight so that the self position can be estimated even when the self position cannot be estimated.

In order to solve such a problem, a storage unit that stores an obstacle map of a flight space, a distance detection sensor that measures a distance to an obstacle existing around an autonomous flight robot, an output of the distance detection sensor, and the Position estimation means for performing processing for estimating a horizontal self-position that is a horizontal self-position in the flight space of the autonomous flight robot and a flight altitude that is a self-position in the height direction using an obstacle map; and the position estimation When the horizontal self-position can be estimated by means, a normal flight control process for controlling movement from the self-position toward a predetermined movement target position, and when the horizontal self-position cannot be estimated by the position estimation means, the flight It has a flight control unit for performing a self position search control process for moving control so that the altitude is high, the autonomously by repeating the respective processes successively Providing autonomous flying robots, characterized in that the rows.

  With this configuration, the autonomous flying robot according to the present invention can detect a position at a high altitude where there is no obstacle from a low altitude position where an obstacle is likely to exist when the position estimation unit cannot estimate the horizontal self-position. By ascending, the autonomous flight can be made to a position where the horizontal self-position can be easily estimated.

  Moreover, as a preferable aspect of the present invention, the self-position search control process further controls movement so as not to move in the horizontal direction.

  With this configuration, when the horizontal self-position cannot be estimated, the horizontal self-position can be avoided while avoiding the danger of a collision with an obstacle or a person existing in the vicinity by ascending directly upward from the position. Can fly autonomously to a position where it is easy to estimate.

Further, as a preferred aspect of the present invention, the flight control means is further capable of estimating the horizontal self-position by the position estimation means, and if the flight altitude is not less than a predetermined threshold value, It is assumed that landing control processing for performing movement control so as to gradually lower the flight altitude without performing self-location search control processing is performed.

  With such a configuration, if the horizontal self-position cannot be estimated even if the position rises to a position equal to or higher than the predetermined threshold by the self-position search control process, the movement control is performed so as to land at the position in the horizontal direction by the landing control process. As a result, it is possible to further improve safety by preventing the state where the horizontal self-position cannot be estimated from being continued unnecessarily.

  Further, as a preferred aspect of the present invention, the position estimation means can further estimate a horizontal self position when the flight control means can estimate the horizontal self position after the self position search control processing is performed. It is assumed that map update processing for updating the obstacle map is performed using the output value of the distance detection sensor at the altitude that was not present.

  With such a configuration, the horizontal self-position can be estimated using the updated obstacle map even when autonomous flight is performed again around the position in the flight space where the horizontal self-position could not be estimated, Since the presence of a new obstacle can be recognized from the updated obstacle map, the risk of collision with the obstacle can be reduced.

  As described above, the autonomous flying robot according to the present invention stably performs the flight so that the self position (horizontal self position) can be estimated even when the self position (horizontal self position) cannot be estimated. It can fly autonomously to the target position.

Overview of autonomous flying robot Functional block diagram of autonomous flying robot Schematic explaining the outline of flight control processing Explanatory drawing which superimposedly displayed 2D point information and the output value of a distance detection sensor Flight control processing flowchart Explanatory diagram of the graph structure in the generation of travel paths Illustration of local target calculation

Hereinafter, while autonomously flying toward a predetermined movement target position in the flight space being monitored with reference to the embodiment accompanying drawings for about autonomous flying robots to retrieve the monitor image of the flight space in the flight details Explained.

  FIG. 1 shows an overview of an autonomous flying robot 1 used in the present embodiment. FIG. 2 shows a functional block diagram of the autonomous flying robot 1 used in the present embodiment. As shown in FIG. 1, in the autonomous flying robot 1 used in the present embodiment, four rotors 2 (propellers) indicated by reference numerals 2a to 2d are present on one plane, and each rotor 2 is not shown in a battery (two This is a quad-rotor type small unmanned helicopter that flies by rotating by a motor 6 driven by a secondary battery. Generally, in a single rotor type helicopter, the azimuth angle is maintained by canceling the counter torque generated by the main rotor with the moment generated by the tail rotor. On the other hand, in a quadrotor type helicopter such as the autonomous flying robot 1 used in the present embodiment, counter torque is canceled by using a rotor 2 that rotates in different directions in front and rear and left and right. For example, when it is desired to rotate the machine body in the yaw direction, a difference is given to the rotational speeds of the front and rear rotors 2a, 2c and the left and right rotors 2d, 2b as indicated by arrows fa to fd. Thus, by controlling the rotation speed of each rotor 2, various movements and adjustments of the posture can be performed.

The imaging unit 3 includes a two-dimensional image sensor having an optical system such as a lens and a two-dimensional array element such as a CCD or CMOS with predetermined pixels (for example, 640 × 480 pixels), and captures captured images of the flight space for a predetermined time. This is a so-called color camera that is acquired at intervals. In the present embodiment, the imaging unit 3 is installed in the housing part so that the optical axis thereof captures the front direction of the autonomous flying robot 1 and is a space obliquely below by a predetermined depression angle θ from the horizontal plane (XY plane). It is installed to take pictures. The acquired captured image is output to the control unit 7 described later, and is stored in the storage unit 8 by the control unit 7, or transmitted to an external device (not shown) via the communication unit 9 described later.
The communication unit 9 is a communication module for performing wireless communication with an external device by, for example, a wireless LAN or a mobile phone line. In the present embodiment, by transmitting the captured image acquired by the imaging unit 3 to a PC installed in a security center (not shown), it is possible for a security guard or the like to remotely monitor an intruder.

  The distance detection sensor 4 is a sensor that detects a distance between an obstacle existing around the autonomous flying robot 1 and the distance detection sensor 4 and acquires a relative position of the obstacle existing in the sensor detection range. is there. In the present embodiment, a laser scanner is provided as the distance detection sensor 4. The laser scanner performs two-dimensional scanning for each angle of a certain angular sample interval, thereby polar information indicating the distance information from the ground (or floor surface) to an object (obstacle) existing in the horizontal plane at a certain height. Can be obtained as: Here, the two-dimensional scan in the laser scanner means that a search signal that is a laser beam is transmitted radially so as to scan a preset detection area, and is returned after being reflected by an object in the detection area. The distance to the object is calculated from the time difference between transmission and reception, and the direction in which the search signal is transmitted and the calculated distance are obtained. In this embodiment, a laser sensor capable of measuring a distance from an obstacle around the autonomous flying robot is used with an angle sample interval of 0.25 °, a detection angle range of 360 °, and a sensor detection range of 30 m. The distance detection sensor 4 is also used to estimate the flight altitude using distance information measured by reflecting a part of the laser emitted from the laser scanner toward the ground with a mirror 5.

  The storage unit 8 is an information storage device such as a ROM (Read Only Memory), a RAM (Random Access Memory), and an HDD (Hard Disk Drive). The storage unit 8 stores various programs and various data, and inputs / outputs such information to / from the control unit. In the various data, in addition to the 2D point information 81 and voxel information 82 corresponding to the “obstacle map” of the present invention, the movement target position 83, various parameters 84 such as setting values and threshold values used for each process of the control unit 7 are included. In addition, output values from each sensor, captured images, and the like are included.

  The 2D point information 81 is information used to estimate the current flight position (hereinafter referred to as “self position”) of the autonomous flying robot by the position estimation unit 71 described later, and is two-dimensional in a horizontal plane called global coordinates. This is coordinate information of a point set that is expressed on the absolute coordinates and represents the outer shape of an obstacle such as a building in the flight space. In the present embodiment, a plurality of point sets set for each flight altitude are stored in advance in the storage unit 8 as 2D point information, and the point set of the flight altitude corresponding to the flight altitude of the autonomous flying robot is stored in the storage unit. It is assumed that the data is read from 8 and used.

  The voxel information 82 is information that divides the flight space into a plurality of voxels as a voxel space and represents the structure of obstacles in the flight space, and is information that is set in advance by an administrator or the like and stored in the storage unit 8. . In the present embodiment, the flying space is divided into a predetermined size (for example, 15 cm × 15 cm), and voxels located on obstacles such as buildings are defined as “occupied voxels”, and the space where the autonomous flying robot 1 cannot move is defined. It was. A voxel located in the space existing near the occupied voxel is defined as a “proximity voxel”, and a voxel located in an area where other flight is possible is defined as a “free voxel”. Each voxel is given a voxel cost value indicating an occupancy so that it can be used when a movement route is generated by the movement route generation means described later. The voxel cost value of the occupied voxel takes the maximum value, and the voxel cost is calculated from the formula of (voxel cost value) = exp {−λ · (distance from the occupied voxel)} so that the voxel cost value decreases as the distance increases. The value was calculated. Here, λ is a parameter obtained by experiment. A voxel having a voxel cost value equal to or greater than a predetermined threshold is set as a “proximity voxel”. Further, a voxel having a voxel cost value smaller than the threshold value is set as “free voxel”, and the voxel cost value of the voxel regarded as a free voxel is reset to 0. In order to prevent the autonomous flying robot 1 from going outside the predetermined movable space in the flight space, the voxel that is the boundary between the movable space and the outside is set as the occupied voxel.

  The movement target position 83 is position information in the flight space that is the target to which the autonomous flying robot 1 moves, and is set in advance by an administrator or the like as coordinate information indicating a predetermined position (point) and stored in the storage unit 8. Information. In the present embodiment, it is assumed that one piece of coordinate information is stored as the movement target position 83. However, the present invention is not limited to this, and a plurality of pieces of coordinate information are stored so that time and predetermined conditions (for example, illustrated) The movement target position 83 used in the control unit 7 may be switched in accordance with the detection status of the sensor not to be used.

  The control unit 7 includes a computer having a CPU and the like, and includes a position estimation unit 71, a speed estimation unit 72, and a flight control unit 73 as a series of processes for performing self-position estimation processing, speed estimation processing, and flight control processing. It is out.

  The position estimation means 71 performs self-position estimation processing for estimating the current flight position (self-position) of the autonomous flying robot 1 in the flight space based on the outputs of the distance detection sensor 4 and the imaging unit 3. In the self-position estimation process, using the output of the distance detection sensor 4 and the 2D point information 81 stored in the storage unit 8, self-positions x, y (horizontal direction (XY plane direction) in the flight space as self-positions. Hereinafter, a process of estimating a “horizontal self-position”), a flight altitude z that is a self-position in the height direction (Z-axis direction), and a yaw angle ψ that is a rotation angle with respect to the Z-axis is performed.

  In the self-position estimation process, first, the flight altitude z of the self-position is calculated using distance information measured by reflecting part of the laser light emitted from the laser scanner toward the ground with the mirror 5. The distance information measured by the laser scanner is not always accurately measured as the distance to the ground because an object other than a building (such as a luggage or a vehicle) exists on the ground. Therefore, in this embodiment, the flight altitude is estimated by applying the extended Kalman filter to the distance information measured by the laser scanner so that it is not easily affected by obstacles other than these buildings.

Next, in the self-position estimation process, the x, y and yaw angles ψ of the self-position are estimated. Per the estimated self-position x, y, the yaw angle [psi, first reads the set point as a two-dimensional map of the flight space corresponding to the altitude z from the 2D point information 81 stored in the storage unit. Then, using the obtained point set and the output of the laser scanner, the x, y, and yaw angles ψ of the self-position are estimated by known scan matching using an ICP (Iterative Closest Point) algorithm. The ICP algorithm performs a matching process by obtaining a combination that minimizes the Euclidean distance between the two point sets A and B. That is, by matching the point set of the 2D point information 81 with the input point set which is an output value (scan data) acquired from the laser scanner mounted on the autonomous flying robot 1 to correct the position error, global coordinates are obtained. It is possible to estimate the x, y, and yaw angles ψ of the self position at.

Speed estimating unit 72, for use in a path tracking control in the flight control means 7 3 described later, performs current flight speed of the autonomous flying robots _{1 (v x, v y,} v z, v yaw) estimates the handle . In the present embodiment, the flight speed is obtained from the time change of the self position (x, y, z, yaw) estimated by the position estimation means 71. At this time, the flight speed was estimated using an extended Kalman filter in consideration of the influence of measurement errors and the like.

The flight control means 73 uses the self-position (horizontal self-position, flight altitude) estimated by the position estimation means 71 and the flight speed estimated by the speed estimation means 72, and a speed command that is a flight control value at each time. Flight control in which the autonomous flying robot 1 flies toward the movement target position 83 stored in the storage unit 8 by obtaining the value, controlling the motor 6 based on the speed command value, and controlling the rotation speed of the rotor 2. Process. FIG. 3 is a schematic view showing the main points of the present invention, and the outline of the flight control process will be outlined with reference to FIG. In FIG. 3, reference numerals 1a, 1b, and 1c correspond to the positions of the autonomous flying robot 1 at times t, t + 1, and t + 2, respectively, and reference signs A1 and A2 correspond to buildings that are obstacles existing in the flight space. ing. In the figure, at time t and time t + 2, the autonomous flying robot 1 can estimate the horizontal self-position, and in this case, the movement target position 83 represented by the symbol G so as not to collide with the buildings A1 and A2 by the flight control processing. It represents that the movement is controlled toward. On the other hand, at time t + 1, the autonomous flying robot 1b cannot estimate the horizontal self-position due to the presence of the bus C that should not have existed in the flight space. In this case, It represents that movement control is performed to increase the flight altitude by the flight control process.

FIGS. 4A and 4B are diagrams in which the 2D point information 81 at the positions of times t + 1 and t + 2 and the distance information to the obstacle calculated from the output value of the distance detection sensor 4 are superimposed and displayed. In FIG. 4, the coordinate value of the point set of the 2D point information 81 is represented by “◯” indicated by the symbol P, the laser light of the distance detection sensor 4 is represented by the dotted line indicated by the symbol R, and the output value of the distance detection sensor 4 The calculated distance information (coordinate value) to the obstacle is represented by “x” indicated by a symbol P ′. As shown in FIG. 4A, at time t + 1, since the laser beam R is blocked by the obstacle bus C indicated by the alternate long and short dash line, the 2D point information P and the distance detection sensor 4 at the flight altitude of the autonomous flying robot 1b. Since the distance information P ′ to the obstacle calculated from the output value cannot be appropriately matched, the horizontal self-position cannot be estimated. However, the flight control process causes the autonomous flight robot 1 to move to a position higher than the height of the bus C by being controlled so as to increase the flight altitude from the position 1b in FIG. 3 to the position 1c. The laser beam R is not blocked by the bus C. Therefore, as shown in FIG. 4B, at time t + 2, the 2D point information P at the flight altitude of the autonomous flying robot 1c and the distance information P ′ to the obstacle calculated from the output value of the distance detection sensor 4 are obtained. appropriately be matched, so that it is estimated Teisu Rukoto a horizontal self-position. FIG. 5 is a flowchart showing the flight control process, and the details of the flight control process will be described below with reference to FIG.

  In the flight control process, first, it is determined whether or not the landing flag stored as various parameters 84 in the storage unit 8 is ON (ST10). The landing flag is a parameter that is turned ON in ST18 when a landing control process described later is performed, and the default value is OFF. When it is determined in ST10 that the landing flag is not ON (OFF) (ST10-No), it is determined whether or not the horizontal self-position can be estimated by the self-position estimation process in the position estimating means 71 ( ST11). As described above, in the self-position estimation process according to the present embodiment, the horizontal self-position is estimated by matching the input point set that is the output of the distance detection sensor 4 (laser scanner) and the point set of the 2D point information 81. When this matching is performed, a score corresponding to the Euclidean distance between the two point sets is obtained (the score becomes lower as the distance between the point sets becomes larger), and the score is smaller than a predetermined threshold. Consider that the horizontal self-position cannot be estimated. For example, as shown in FIG. 4 (a), the point set of 2D point information P at the flight altitude of the autonomous flying robot 1b and the input of distance information P ′ to the obstacle calculated from the output value of the distance detection sensor 4 are input. When the Euclidean distance is large between the point sets, it is considered that the horizontal self-position cannot be estimated because the score is low. In the present embodiment, it is determined whether or not the horizontal self-position can be estimated based on the score, but the present invention is not limited to this. For example, the points of the input point set whose position is significantly different from the point set of the 2D point information 81 are excluded from the matching process as “outliers”, but when the number of outliers is equal to or greater than a predetermined threshold, the horizontal self A method in which the position cannot be estimated may be used.

ST11 when horizontal self-location is determined to come estimated at (ST11-Yes), a flight control process in the flight control means 73 during normal (when the horizontal self-location is able to estimate), normal flight control Processing is performed (ST12 to ST14). In the normal flight control process, first, the movement path for calculating the movement path of the autonomous flying robot using the voxel information 82 and the movement target position 83 stored in the storage unit 8 and the self-position calculated by the position estimation means 71. Generation processing is performed (ST12). Specifically, in the movement route generation process, first, the voxel information 82 is read from the storage unit, and the center of each voxel of the free voxel and the adjacent voxel that is the divided movable space is set as a node, and the node adjacent to the node A graph structure is generated with the line segments connecting the edges as edges. FIG. 6 is a diagram for explaining the graph structure, in which a part (27) of movable voxels (free voxels or adjacent voxels) in the flight space is cut out. In FIG. 6, each cube represented by the symbol B represents a free voxel or a neighboring voxel. Further, a sphere filled with black or hatching at the center of these voxels B is a node, and a line segment displayed with a dotted line connecting the nodes is an edge. After generating the graph structure for all movable voxels based on the voxel information 82 in this way, from the voxel node where the autonomous flying robot 1 exists to the voxel node where the movement target position 83 exists. Generate a travel route. Although various route generation methods can be applied to the generation method of the movement route, in the present embodiment, the movement route is searched using the A * (Aster) route search method. At this time, the voxel cost stored as the voxel information 82 is used as a movement cost in the A * route search method. Data of the movement path generated generated by the flight control means 7 3 is a set data of the transit point (x, y, z), the information is temporarily stored in the storage unit 8.

  Next, as a normal flight control process, a process of calculating the nearest position (hereinafter referred to as a “local target”) to be targeted by the autonomous flying robot at the current time is performed (ST13). FIG. 7 is a diagram for explaining the calculation of the local target. In calculating the local target, the flight control means 73 reads the movement route generated in ST13 from the storage unit 8, and the via point Wp1 that the autonomous flying robot 1 is aiming at at the current time and the via point Wp0 that has passed the previous time. A straight line W connecting the two points is obtained. Then, the flight control means 73 calculates the intersections Lp ′ and Lp between the obtained straight line W and the sphere S centered on the self-position of the autonomous flying robot 1, and sets the intersection Lp close to the target via point Wp 1 as the local target. Asking. In this way, by performing flight control so that the autonomous flying robot 1 moves toward the local target at each time, the local target always moves on the moving path toward the moving target position 83, and the autonomous flying robot 1 Will fly along the path of travel.

Next, as normal flight control processing, speed command values u _x , u _y , u _z , u _ψ are calculated for each direction of X, Y, Z, and yaw angle ψ so as to fly toward the calculated local target. Processing is performed (ST14). At this time, a speed command value is determined so that the difference between the current self position and the position of the local target is small. Specifically, the speed command value u = (u _x , u _y , u _z ) in the XYZ direction is estimated by the self position r = (x, y, z) obtained by the position estimation unit and the speed estimation unit. Using velocity v = (v _x , v _y , v _z ), it is obtained by PID control. When each speed command value in the XYZ-axis directions is u = (u _x , u _y , u _z ) and the local target is r ′ = (x, y, z), the speed command value is u = K _p (r '-R) + K _d · v + K _i · e is calculated. Here, K _p , K _d , and K _i are gains of PID control, respectively, and e = (e _x , e _y , e _z ) is an integrated value of errors. On the other hand, the speed command value u _ψ in the yaw angle direction includes the target angle of ψ ′, the attitude (angle) of the autonomous flying robot 1 estimated by the position estimating means 71, and the angular velocity estimated by the speed estimating means 72 of v _yaw. When obtained by the PD control as equation _{u ψ = K p (ψ'-} ψ) + K d · v ψ. In the present embodiment, the target angle ψ ′ is an angle that faces the direction of the movement target position 83 (G).

Subsequently, when the horizontal self-location is determined not come in estimator at ST11 (ST11-No), (a 8m in the present embodiment) the current altitude is stored in advance in the storage unit 8 below the threshold It is determined whether or not (ST15). When it is determined in ST15 that the current flight altitude is 8 m or less (ST15-Yes), the flight control means 73 performs a self-position search control process as a flight control process for estimating the horizontal self-position (ST16). ). In the self-position search control process, the flight control means 73 obtains a speed command value u = (u _x , u _y , u _z ) that gradually increases the flight altitude of the autonomous flying robot 1, and uses the speed command value u. The rotation speed of the rotor 2 is controlled. In this embodiment, the speed command values u _x and u _y in the X and Y axis directions are set to 0 so that the autonomous flying robot 1 does not move in the horizontal direction, and the speed command value uz in the Z axis direction is obtained by experiments. It is a predetermined value.

Subsequently, when it is determined in ST15 that the current flight altitude is not less than 8 m (ST15-No), the flight control means 73 performs landing control processing (ST17). In the landing control process, the flight control means 73 obtains a speed command value u = (u _x , u _y , u _z ) that gradually lowers the flight altitude of the autonomous flying robot 1, and the rotor 2 is determined based on the speed command value u. The number of rotations is controlled. In this embodiment, in order to prevent the autonomous flying robot 1 from moving in the horizontal direction, the velocity command values u _x and u _y in the X and Y axis directions are set to 0, and the velocity command value u _z in the Z axis direction is tested. The predetermined value obtained by When the landing control process of ST17 is performed, the flight control means 73 performs a process of changing the landing flag of the storage unit 8 to ON (ST18). In this way, by changing the landing flag to ON, the flight altitude can be continuously lowered without changing the speed command value in the next flight control process in the determination of ST10. In the present embodiment, the flight control process is performed until the autonomous flight robot 1 has landed on the ground, and when the autonomous flight robot 1 has landed (when the flight altitude is estimated to be 0), the rotor It is assumed that the rotation of 2 is controlled to stop.

  In this way, the control unit 7 sequentially repeats the processes in the position estimation unit 71, the speed estimation unit 72, and the flight control unit 73 described above every predetermined time. Thereby, when the horizontal self-position can be estimated, the autonomous flying robot 1 of the present embodiment can move autonomously toward the movement target position 83 by performing movement control by normal flight control. In addition, when the horizontal self-position cannot be estimated, by moving control so as to increase the flight altitude by self-position search control, from a low altitude position where obstacles are likely to exist, You can move to a position. At this time, without moving in the horizontal direction, it is possible to avoid the danger of a collision with an obstacle, a person, or the like existing in the vicinity by ascending directly above the horizontal self-position. As described above, the autonomous flying robot 1 can move to a position where the horizontal self-position can be easily estimated while maintaining safety even when the horizontal self-position cannot be estimated.

  Also, if the horizontal self-position cannot be estimated even if the self-position search control process rises to a position equal to or higher than a predetermined threshold (for example, 8 m), the landing control process should land at the position in the horizontal direction. By controlling the movement, the state where the horizontal self-position cannot be estimated is not continued unnecessarily, and the safety can be further improved.

  By the way, the present invention is not limited to the above-described embodiment, and may be implemented in various different embodiments within the scope of the technical idea described in the claims. Further, the effects described in the embodiments are not limited to this.

  In the above embodiment, when the self-position can be estimated by the self-position search control process, the autonomous movement toward the movement target position 83 is made again by shifting to the normal flight control process. However, the present invention is not limited to this, and when the self-position can be estimated by the self-position search control process, the position estimation means 71 uses the output value of the distance detection sensor at the flight altitude at which the horizontal self-position could not be estimated, to obtain 2D point information. And map update processing for updating the voxel information 82 may be performed. That is, the flight altitude when the horizontal self-position could not be estimated and the output value of the distance detection sensor (coordinate values of the input point set) are associated with each other and temporarily stored in the storage unit 8, and self-position search control is performed. When the horizontal self-position can be estimated by rising straight up by processing, the output value of the distance detection sensor temporarily stored is assumed to be true, and the correspondence in the 2D point information 81 stored in the storage unit 8 using the output value Change the value of the flight altitude (the flight altitude for which the horizontal self-position could not be estimated). Similarly, the voxel information 82 stored in the storage unit 8 is a set of input points that are voxels at a flight altitude where the horizontal self-position could not be estimated and whose horizontal position is significantly different from the position of the occupied voxel. And voxels that interfere with the set of input points are updated as occupied voxels. Then, the voxel existing near the occupied voxel is updated as a neighboring voxel. Thereby, even if it is a case where it flew autonomously to the position of this periphery again, while being able to estimate a horizontal self position, the danger of the collision to the obstacle which exists in the updated position can be reduced.

  In the above-described embodiment, a laser scanner is used as the distance detection sensor 4. However, the present invention is not limited to this, and for example, an infrared distance sensor, a millimeter wave radar (microwave radar), an ultrasonic distance sensor, or the like may be used.

In the above embodiment, in order to calculate the speed command value by the flight control means 7 3, calculates the self speed at speed estimating unit 72. However, the present invention is not limited to this, and the speed command value may be calculated without the speed estimation means 72 and without calculating the self speed . Also, in the above embodiment, it calculates the self speed based on the self position at a rate estimation means 72. However, the present invention is not limited to this. A sensor that uses a sensor such as an IMU (Internal Measurement Unit) or a camera that captures an image directly below the autonomous flying robot 1 is installed, and is known based on an image captured from the camera. The self velocity may be calculated using an optical flow method.

  In the above embodiment, the control unit 7 performs a series of processing of position estimation processing (self-position estimation processing, moving object position estimation processing), speed estimation processing, route search processing, and route tracking control processing. However, the present invention is not limited to this, and a control PC (not shown) may be prepared and the PC may perform a series of these processes. That is, the autonomous flying robot 1 transmits the output of the laser scanner of the distance detection sensor 4 and the captured image acquired by the imaging unit 3 to the PC by wireless communication via the communication unit 9. Then, the PC performs position estimation processing, speed estimation processing, and flight control processing, and transmits the speed command value obtained in the flight control processing to the autonomous flying robot 1 by wireless communication. Then, the autonomous flying robot 1 flies to a target position by controlling the number of revolutions of the motor 6 based on the speed command value received via the communication unit 9. As described above, by sharing the above-described series of processes using the external PC, it is possible to reduce the CPU processing load of the autonomous flying robot 1 and to suppress the battery consumption.

DESCRIPTION OF SYMBOLS 1 ... Autonomous flight robot 2 ... Rotor 3 ... Imaging part 4 ... Distance detection sensor 5 ... Mirror 6 ... Motor 7 ... Control part 8 ... Memory | storage part 9 ... -Communication part 81 ... 2D point information 82 ... Voxel information 83, G ... Movement target position 84 ... Various parameters 71 ... Position estimation means 72 ... Speed estimation means 73 ... Flight Control means A1, A2 ... Building C ... Bus B ... Voxel R ... Laser beam P ... Coordinate value of 2D point information P '... Coordinate value of distance detection sensor output value Lp ... Local targets

Claims (4)

A storage unit storing an obstacle map of the flight space;
A distance detection sensor that measures the distance to obstacles around the autonomous flying robot;
Using the output of the distance detection sensor and the obstacle map, a process of estimating a horizontal self-position that is a horizontal self-position and a flight altitude that is a self-position in the height direction in the flight space of the autonomous flight robot is performed. Position estimation means;
When the position estimator can estimate the horizontal self-position, when the position estimator cannot estimate the horizontal self-position, and the normal flight control process for controlling the movement from the position to the predetermined movement target position And a flight control means for performing a self-position search control process for controlling the movement so that the flight altitude becomes high, and autonomously flying by repeating each process sequentially.   The autonomous flight robot according to claim 1, wherein the self-position search control process further controls movement so as not to move in a horizontal direction. The flight control means further performs the self-position search control process when the position estimation means cannot estimate the horizontal self-position and the flight altitude is equal to or greater than a predetermined threshold. The autonomous flying robot according to claim 2, wherein landing control processing is performed to perform movement control so as to gradually decrease the flight altitude. The position estimation means further includes the distance detecting sensor at an altitude at which the horizontal self-position could not be estimated when the horizontal self-position could be estimated after the flight control means performed the self-position search control processing. The autonomous flying robot according to claim 2, wherein map update processing is performed to update the obstacle map using an output value.

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