KR20210046501A - unmanned mowing robot and automatic driving method thereof - Google Patents

Abstract

The present invention is to provide a control apparatus for autonomous driving of an unmanned lawn mower robot capable of setting an optimal driving path by correcting a lateral error according to the size of a landmark, and a control method thereof. According to the present invention, a driving method of an unmanned lawn mower robot comprises the steps of: obtaining, by a radar sensor, a distance value and an angle value from a reflected signal of a radar signal transmitted to a landmark defining a work space; acquiring, by a camera sensor, an image by photographing the landmark; correcting, by a path calculating unit, the angle value among the distance value and the angle value input from the radar sensor by using the image input from the camera sensor, and using the distance value and the corrected angle value to calculate a driving path in the work space; and driving, by a driving device, the unmanned lawn mower robot according to the calculated driving path.

Description

TECHNICAL FIELD [0001] Unmanned mowing robot and automatic driving method thereof

The present invention relates to an unmanned lawn mower robot, and more particularly, to an autonomous driving technology of an unmanned lawn mower robot.

In the conventional literature, which is '10-2004-0013116' as the application number, the left and right independent continuously variable transmissions are operated, and a pair of left and right steering levers are operated in the front/rear direction to operate these continuously variable transmissions separately. A lawnmower for passenger use is disclosed in which a lawnmower for passenger use can be made to move forward or backward or rotate in one direction to perform a turn on the spot.

This conventional document is a mechanical system for manual lever operation, and manual lever operation is inconvenient and inefficient in simple repeated weeding operations.

Recently, research on an unmanned lawn mower robot has been actively conducted in order to solve the inconvenience of such a manual lever-operated lawn mower.

The unmanned lawnmower robot should basically be capable of autonomous driving. For such autonomous driving, it is necessary to recognize a work space in which weeding is to be performed, estimate one's position within the recognized work space, and find an optimal driving route for autonomous driving based on this position estimation.

The existing unmanned lawnmower robot recognizes surrounding environment information to recognize a work space and set an optimal driving route. First, a plurality of landmarks having a certain shape are simply placed at the corners of the space to be worked. A sensor (for example, a radar device) mounted on an unmanned lawnmower robot recognizes a work space by itself in a manner that recognizes a landmark, and sets an optimal driving route by itself.

On the other hand, conventional landmarks generally have a plate shape of a certain size. If the size (area) is large, when the radar signal reflects, it is difficult to estimate the position in the work space due to a lateral error (or a longitudinal error). There may be difficulties. In order to reduce such lateral error, there is also a limit to making the size of the landmark small.

An object of the present invention is to provide a control device for autonomous driving of an unmanned lawnmower that can set an optimal driving route by correcting a lateral error according to the size of a landmark, and a control method thereof.

In addition, the present invention provides an unmanned lawn mower robot capable of autonomous driving based on a set optimal driving route.

The object of the present invention is not limited to the object as described above, and other technical problems may exist.

A driving method of an unmanned lawn mower robot according to an aspect of the present invention for achieving the above object includes: obtaining, by a radar sensor, a distance value and an angle value from a reflection signal of a radar signal transmitted to a landmark defining a working space; Obtaining an image by photographing the landmark by a camera sensor; The path calculation unit corrects the angle value from the distance value and the angle value input from the radar sensor using the image input from the camera sensor, and uses the distance value and the corrected angle value to the work space. Calculating a driving route within the vehicle; And driving, by the driving device, the unmanned lawn mower robot according to the calculated travel path.

An unmanned lawnmower robot according to another aspect of the present invention includes a route calculating device for calculating a travel path and a driving device for driving autonomous driving of the unmanned lawnmower robot according to the calculated travel path, and the route calculating device, A radar sensor that obtains a distance value and an angle value from a reflected signal of a radar signal transmitted to a landmark defining a working space; A camera sensor that captures the landmark and acquires an image; And correcting the angle value from the distance value and angle value input from the radar sensor using the image input from the camera sensor, and using the distance value and the corrected angle value in the working space. And a route calculation unit that calculates the travel route.

According to another aspect of the present invention, a method for setting a path of an unmanned lawnmower robot capable of autonomous driving includes: obtaining, by a radar sensor, a distance value and an angle value from a reflected signal of a radar signal transmitted to a landmark; Obtaining an image by photographing the landmark by a camera sensor; Correcting, by a path calculator, the angle value using the image; Selecting, by the route calculator, a target landmark from among a plurality of landmarks based on the distance value and the corrected angle value; Generating, by the route calculator, a traveling route following the selected target landmark; And calculating, by the route calculating unit, a target speed value and a target attitude angle corresponding to the traveling route.

According to the present invention, according to the route setting method of the unmanned lawnmower robot according to the present invention, by placing the landmark at the corner of the desired work space, it is possible to easily set the work space. In addition, since the working space is divided into grid intervals with a unit interval smaller than the weeding width of the lawnmower robot, and the travel path is calculated, tight weeding is possible. In addition, since it performs location tracking by referring to landmarks in real time, it is more accurate and less delayed than when location tracking is performed using only GPS and its own sensors. It is possible to correct in real time.

In addition, the present invention enables automatic driving and automatic steering control of an engine-driven lawn mower operated with a lever, so that the weeding operation can be performed by automatic operation, and the weeding operation is performed by automatic operation in a work space requiring repetitive operation. By doing so, the user's convenience is high, and efficiency can be increased by configuring an automatic operation and automation system of various mechanical devices operated by levers.

1 is a block diagram showing the internal configuration of an unmanned lawn mower robot according to an embodiment of the present invention.
2 and 3 are views for explaining the shape and size of a landmark according to an embodiment of the present invention.
4 is a flowchart illustrating a process of setting a driving route of the unmanned lawn mower according to an embodiment of the present invention.
5 is a perspective view showing the appearance of the unmanned lawn mower robot according to an embodiment of the present invention.
6 is an enlarged view of an enlarged portion A of FIG. 1.
7 is a block diagram of a control device for automatic driving of the engine-driven lawn mower shown in FIGS. 1 and 2;
FIG. 8 is a diagram for explaining a target speed and a target attitude angle input by the subtractor shown in FIG. 3;
9 is a view for explaining a method for calculating left and right wheel speeds performed by the integrated control unit shown in FIG. 3.
10 is a flowchart illustrating a control method for autonomous driving of an engine-driven lawn mower according to an embodiment of the present invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those of ordinary skill in the art may easily implement the present invention. However, the present invention may be implemented in various different forms and is not limited to the embodiments described herein. In the drawings, parts irrelevant to the description are omitted in order to clearly describe the present invention, and similar reference numerals are attached to similar parts throughout the specification.

1 is a block diagram showing an internal configuration of an unmanned lawn mower robot according to an embodiment of the present invention.

Referring to FIG. 1, an unmanned lawn mowing robot 500 according to an embodiment of the present invention includes a route setting device 50 and a driving device 300.

The route setting device 50 sets an optimal driving route for autonomous driving of the unmanned lawnmower 300, and a target speed value (v _t ) and a target attitude angle (or target steering angle) corresponding to the set driving route ( θ _t ) is calculated and input to the driving device 300.

The driving device 300 drives the unmanned lawnmower 300 to enable autonomous driving according to the _{optimal travel paths v t} and θ _t set by the route setting device 50.

The route setting device 50 includes a radar sensor 51, a camera sensor 53, and a route calculation unit 55 in order to set an optimal travel route.

The radar sensor 51 transmits a radar signal to a landmark 10 to receive a reflected signal generated by reflecting the radar signal to the landmark 10.

The radar sensor 51 processes the received reflected signal to obtain a distance value R _N and an angle value θ _{N of} the landmark 10, and inputs them to the path generator 55.

The camera sensor 53 captures the landmark 10 to obtain an image including the landmark 10, and inputs it to the path generator 55.

The image acquired by the camera sensor 53 is a lateral error of the radar sensor 51 that occurs according to the size (width or width) of the landmark 10 (hereinafter,'error of the angle value (θ _N )'). It is used to correct).

The route calculation unit 55 provides an optimal driving route (v _t , _{corresponding to the distance value R N} and the angle value θ _{N) input from the radar sensor 51.} θ _t ) is generated and input to the driving device 300. Here, v _t is the target speed value, and θ _t is the target attitude angle (target steering angle).

On the other hand, when the size of the landmark 10 is large, an angle θ _N error corresponding to a lateral error of the radar sensor 51 may occur.

_{In order to correct the error of the angle (θ N} ) of the radar sensor 51, the path calculation unit 55 uses the angle value θ based on the image including the landmark 10 input from the camera sensor 53. Correct the error of _{N ).}

_{Specifically, in order to correct the error of the angle value (θ N} ), the path calculation unit 55 first calculates the distance value and the angle value (R _N , θ _N ) obtained from the radar sensor 51 from the camera sensor. It converts into _{UV coordinates (U N} , V _N ) that can be represented on the acquired image.

This is a process of converting distance values and angle values (R _N , θ _N ) expressed in the radar coordinate system into values expressed in the camera coordinate system of the camera sensor 53.

For this coordinate system transformation, a transformation matrix may be used. For example, by multiplying a transformation matrix with a distance value and an angle value (R _N , θ _N ) by a matrix, UV coordinates (U _N , V _N ) can be obtained from this. Since a description of the transformation matrix is well known, a detailed description thereof will be omitted.

Subsequently, the path calculation unit 55 searches for the center point 10 ′ of the landmark 10 based _{on the converted UV coordinates (U N} , V _{N) on the image, and when the center point 10 ′ is searched,} From the radar sensor 51 using the difference value (distance value on the image) between _{the UV coordinates (U c} , V _c ) corresponding to the searched center point (10') and the converted UV coordinates (U _N , V _N) The error of the obtained angle value (θ _{N) is corrected.}

By doing so, it is possible to correct an error _{of the angle θ N} of the radar sensor 51 that occurs when the size of the landmark 10 is large.

When the corrected angle value is θ _N ', the path calculation unit 55 calculates the optimal driving paths (V _t and θ _t ) _{using the distance value R N} and the corrected angle value θ _{N ′.} Recalculate and regenerate.

On the other hand, _{the travel paths V t} and θ _t recalculated by correction of the _{angle value θ N} error are calculated in real time rather than only once within the entire work space of the unmanned lawn mower 500.

For real-time processing, first, the lawnmower 500 sets up a work space.

For example, in a state in which a plurality of landmarks 10 are installed at the corners of a work space to be worked, the lawnmower 500 does not move and rotates in place, while the camera sensor 53 10). At this time, the landmark must be within a distance that can be identified by the camera sensor 53.

For the recognition of the landmark 10, the path calculation unit 55 may use a background removal algorithm and an object extraction algorithm for extracting an object from the image, and the center point 10 of the landmark 10 mentioned above. ') It can also be obtained from the landmark image extracted through the background removal algorithm and the object extraction algorithm. For example, the UV coordinates corresponding to the center point 10' among UV coordinates constituting the landmark image are calculated.

When the landmark image is acquired, the path calculation unit 55 calculates and sets the entire work space using the relationship between the size of the landmark image and the distance from the lawnmower 500 to the actual landmark.

Here, the entire work space may be set using the radar sensor 51, but since the angle (θ _N ) error of the radar sensor 51 must be corrected using the image acquired from the camera sensor 53, the entire work space is The camera sensor 53, not the radar sensor 51, should be set based on the image acquired by recognizing the landmark 10.

That is, since the radar sensor 51 is wider than the camera sensor 53 in the recognizable range of the landmark 10, even if the radar sensor 51 recognizes the landmark 10, the camera sensor 53 There may be cases where the mark 10 cannot be recognized. In this case, since the camera sensor 53 cannot acquire an image including the landmark _{, the error of the angle value θ N} of the radar sensor 51 cannot be corrected.

Therefore, the working space needs to be limited to the distance at which the camera sensor 53 can identify the landmark, not the radar sensor 51.

In this way, when the entire work space is set based on the camera sensor 53, the path calculation unit 55 divides the grid spacing in units smaller than the weeding width of the lawnmower 500 within the entire work space, and The driving path (v _t , θ _t ) corresponding to the distance value (R _N ) and the corrected angle value (θ _N ') at every interval, that is, the target speed value (v _t ) and the target attitude angle (θ _t ) Calculate.

The route calculation unit 55 for calculating the optimal travel route includes a processor that performs an operation process related to route setting, and a memory that permanently and/or temporarily stores intermediate data and/or result data processed by the processor. It may be configured to include, or may be implemented only as a processor. When the path generation unit 55 is implemented only as a processor, the memory may be disposed outside the path generation unit 55.

Meanwhile, the landmark 10 may have a certain shape and size.

2 and 3 are views for explaining the shape and size of a landmark according to an embodiment of the present invention, and FIG. 2 is a front view of the landmark, and FIG. 3 is a side view of the landmark.

2 and 3, the landmark 10 may be manufactured in a tetrahedral shape consisting of four faces, and one of the four faces has an OPEN structure.

The landmark 10 is installed on the support 20 so that one open side is perpendicular to the ground. The support 20 has wheels to enable the movement of the landmark 10.

The landmark 10 is manufactured to have the same height (for example, 1500 mm) as the height of the radar sensor attached to the front of the lawnmower 500 in order to secure the maximum reflectance.

The landmark 10 is designated at a distance of 60m from the position of the lawnmower 500 in order to maximize the working space of the lawnmower 500.

In order to secure a maximum of 60m, Azimuth Field of View 90deg, the reflectance of the landmark 10 must be 10dB or more, and for this, the landmark has a width of 2m (2000 mm) and a tetrahedral shape (the radar signal is the center of the landmark. So that it is focused on the side).

4 is a flowchart illustrating in detail a process of setting a driving route of the unmanned lawn mower according to an embodiment of the present invention.

Referring to FIG. 4, first, in S511, a work space is set based on a camera sensor. Specifically, while the plurality of landmarks 10 are installed at the corners of the work space to be worked, the lawnmower 500 does not move and rotates in place, while the camera sensor 53 ) Is captured to obtain an image including the landmark 10, and inputs it to the route calculator 55, so that the route calculator 55 recognizes the landmark 10. At this time, the landmark 10 must be within a distance that can be identified by the camera sensor 53. When the image is acquired, the path calculation unit 55 uses the relationship between the size of the landmark included in the predefined image and the distance from the lawnmower 500 to the actual landmark. The entire workspace is calculated and set based on the size of the landmark. When the work space is set, the path calculation unit 55 divides the entire work space into a grid spacing in units smaller than the weeding width of the lawnmower 500.

Subsequently, in S513, when the setting of the working space divided by the grid interval is completed, the radar sensor 51 receives the reflected signal for the radar signal transmitted to the landmark 10, and processes the reflected signal to process the radar sensor. A distance value (R _N ) and an angle value (θ _N ) of (51) are obtained, and these are input to the path calculator 55.

_{Subsequently, in S515, the path calculation unit 55 corrects the error of the angle value θ N} input from the radar sensor 51 based on the image input from the camera sensor 53 to adjust the size of the landmark 10. Correct the lateral error accordingly. Specifically, the distance value and angle value (R _N , θ _N ) acquired by the radar sensor 51 are converted into _{UV coordinates (U N} , V _N ) of the image acquired by the camera sensor 53. Subsequently, the center point 10' of the landmark 10 is searched based on the converted UV coordinates (U _N , V _N ) on the image, and when the center point 10' is searched, the searched center point 10' Calculate the difference value (distance value on the image) between the UV coordinates (U _c , V _c ) and the converted UV coordinates (U _N , V _N ) corresponding to, and use the calculated difference value to calculate the angle value (θ _N ) is corrected.

Subsequently, in S517, the path calculator 55 selects a target landmark from among the plurality of landmarks based on the _{distance value R N} and the corrected angle value θ _N. The size and installation location of each landmark is information known in advance, and based on this, after setting the reference distance range and the reference angle range for each landmark, the distance value currently input from the radar sensor 51 (R _N ) And the corrected angle value (θ _N ) belong to a certain reference distance range and a reference angle range, a landmark defined by that reference distance range and a reference angle range is selected as the target landmark.

Subsequently, in S519, the route calculation unit 55 assigns a track ID to the selected target landmark.

_{Subsequently, in S521, the path calculation unit 55 calculates and generates the travel paths v t} and θ _t following the target landmark to which the track ID is assigned, in units of grid intervals partitioned in the work space.

Subsequently, in S523, the route calculation unit 55 _{inputs the travel routes v t} and θ _t to the driving device 300.

Subsequently, in S525, the driving device 300 _{drives the lawnmower 500 according to the input travel paths v t} and θ _t to start the lawnmower 500.

Subsequently, in S527, while the lawnmower 500 is traveling, the path calculator 55 determines in real time whether a change of the target landmark has occurred. For example, the difference value (|R _{i-1 ━} R _i |) between the previously input distance value (R _{i - 1} ) and the currently input distance value (R _i ) from the radar sensor 51 is the first threshold. It is smaller than (α), before the angle value inputted to the _- angle values corrected to _{(θ i 1) (θ i} -1 ') adjusted for the current input angle values (θ _i) the angle values (θ _i') If the difference value with (|θ _{i-1 ━} θ _i |) is less than the second threshold value (β), it is determined that there is no change in the target landmark, and S521, S523 and S525 are repeated, and vice versa. In S517, the target landmark is newly selected again, and then S519, S521, S523, and S525 are repeatedly performed.

Subsequently, in S529, while the lawn mower robot 500 is traveling while changing the target landmark, it is determined whether it has reached a grid interval corresponding to the destination included in the traveling route, and when it arrives, the lawn mower robot 500 runs. And by ending the weeding operation, the whole series of processes is ended.

As described above, according to the route setting method of the unmanned lawn mower according to the present invention, by placing the landmark at the corner of the desired work space, it is possible to easily set the work space. In addition, since the working space is divided into grid intervals with a unit interval smaller than the weeding width of the lawnmower robot, and the travel path is calculated, tight weeding is possible. In addition, since it performs location tracking by referring to landmarks in real time, it is more accurate and less delayed than when location tracking is performed using only GPS and its own sensors. It is possible to correct in real time.

Hereinafter, a driving device for driving an unmanned lawnmower robot according to a travel path set by the path setting device of the present invention will be described.

5 is a perspective view showing the appearance phenomenon of an engine-driven lawn mower according to an embodiment of the present invention, FIG. 6 is an enlarged view of part A of FIG. 1, and FIG. 7 is shown in FIGS. 1 and 2 It is a block diagram of a control device for automatic driving of an engine-driven lawn mower, and FIG. 8 is a diagram for explaining a target speed and a target steering angle input to the subtractor shown in FIG. 7.

First, referring to FIG. 7, a driving device 300 according to an exemplary embodiment of the present invention is mounted on a lawnmower 500 that is driven by an engine driving type.

The driving device 300 largely includes a control device 100, a lever 210, and an engine 220.

The control device 100 controls the autonomous driving (automatic driving and automatic steering) of the lawnmower 500 by automatically operating the lever 210 and driving the engine 220 according to the automatic operation of the lever 210 do.

To this end, the control device 100 includes an adder and subtractor 110, an integrated control unit 120, a motor controller 130, a motor unit 140, a gear unit 150, and a sensor. It includes a unit 160 and an error calculation unit 170.

Here, among the configurations in the control device 100, the remaining configurations 110, 120, 130, 160 and 170 excluding the motor unit 140 and the gear unit 150 are not shown in FIGS. 5 and 6, and the The rest of the components are assumed to be mounted inside a housing that forms the exterior of an engine-driven lawn mower. Of course, depending on the design, the motor unit 140 and the gear unit 150 may also be mounted inside the housing.

Adder/Subtracter(110)

The adder and subtractor 110 bypasses a target speed (Target Mower Speed) (v _t ) and a target attitude angle (or target steering angle) (θ _t ) initially input from an input unit (not shown). bypass) and input to the integrated control unit 120.

In addition, the adder and subtractor 110 is a speed error (v _{error ) for the actual speed (v m ) of the lawnmower corresponding to the target speed (v t} ) and the lawnmower corresponding to the target attitude angle (θ _t ). The attitude angle error (θ _error ) with respect to the actual steering angle (θ _m ) is fed back from the error calculation unit 170, and the speed error (v _error ) and the attitude angle error (θ _error ) are calculated as the target speed (v _t ) and the target attitude. _{The error between the actual speed (v m} ) and the actual attitude angle (θ _m ) is compensated for by adding or subtracting the angle (θ _{t ).}

The target speed (v _t ) and the target attitude angle (θ _t ) are pre-calculated and set values, and for the pre-calculation of the target speed (v _t ) and the target attitude angle (θ _t ), the engine-driven lawn mower robot is separately It may be configured to further include a sensor (camera, ultrasonic or infrared sensor) (not shown) and a separate processor unit (not shown).

The target speed (v _t ) and the target attitude angle (θ _t ) are, for example, as shown in FIG. Work space), while the lawnmower robot rotates in place at a certain position inside and outside the work space, and recognizes the landmark through various sensors provided therein, and then the processor unit returns the landmark 40 The work space is divided into grid intervals according to the recognition result value, and the optimal travel path (zig-zag, eddy direction) is calculated from the partitioned grid spacing, and the target for each segmented grid spacing from the calculated optimal travel path. It is possible to calculate the speed (v _t ) and the target attitude angle (θ _{t ).} The explanation for this has been sufficiently explained above.

Integrated control unit 120

Referring back to FIG. 7, the integrated control unit 120 is the left wheel speed (ω _L , _{) according to the target speed (v t} ) and the target attitude angle (θ _{t) input from the adder and subtractor 110.} Left Wheel speed) and Right Wheel speed (ω _R , Right Wheel speed) is calculated and transmitted to the motor control unit 130.

[Calculate left and right wheel speed]

9 is a diagram illustrating a method of calculating left and right wheel speeds performed by the integrated control unit illustrated in FIG. 7.

Referring to FIG. 9, in the calculation of the left and right wheel speed, the turning radius of the differential steering system model composed of a drive wheel and a caster wheel is calculated, and the left and right wheel speeds corresponding to the target speed and the target attitude angle are calculated. You can get it. That is, the calculated turning radius is expressed as an equation for the left and right wheel speed, and the left and right wheel speed can be obtained by arranging this.

The calculation of the left and right wheel speed is as follows.

The total speed v of the lawnmower 500 may be calculated as the left and right wheel angular speeds as shown in Equation 1 below.

Where v _R is the right wheel speed, v _L is the left wheel speed and r is the tire radius.

By knowing the heading angle of the lawnmower robot, the turning radius R can be obtained as shown in Equation 2 below.

,

는 선회 각속도(요레이트)이고, 선회 각속도는 잔디 깎기 로봇의 좌우 휠 트레드(도 9의 t, 횡방향 길이)에 대한 휠 속도 차이로 계산되며, 아래의 수학식 3으로 나타낼 수 있다.here,

Is the turning angular velocity (yaw rate), and the turning angular velocity is calculated as the difference in wheel speed with respect to the left and right wheel treads (t in FIG. 9, lateral length) of the lawnmower, and can be expressed by Equation 3 below.

Using the above-described equations, the turning radius can be expressed as an equation for the left and right wheel speeds, as shown in Equation 4 below.

By substituting the speed equation of Equation 1 to the turning radius equation summarized by Equation 4, each left and right wheel speed can be summarized by Equation 5 below.

Motor control unit 130

The motor control unit 130 refers to a lookup table representing the relationship between the left and right wheel speeds and the left and right lever positions, and the left lever position mapped to _{the left wheel speed ω L input from the integrated control unit 120 (} Generates a left motor driving signal (L _{L ) corresponding to Left Lever Position) and a right motor driving signal (L R} ) corresponding to the right lever position (Mapping) to the right wheel speed (ω _{R ).} do.

The right motor driving signal L _R represents the rotor position value (rotor angle value) of the right motor 142 included in the motor unit 140, and the left motor driving signal L _L is the motor unit 140 It represents the rotor position value (rotor angle value) of the left motor 144 included in.

The lookup table may be generated in advance and stored in a storage means (eg, memory) in order to map the left and right wheel speeds to the positions of the left and right levers.

The method of generating the lookup table is, for example, first, by moving the rotor position value (rotor angle value) of the motor 140 step by step and measuring the wheel speed with an RPM gauge. When the lawnmower 500 includes a lawn speed sensor, the lawn speed sensor may measure the lawn speed. Thereafter, a look-up table is generated by programming the rotor position value and wheel speed by step, and stored in a storage means such as a memory.

Motor(140)

The motor 140 includes a right motor 142 and a left motor 144 as shown in FIGS. 5 and 7.

The right motor 142 generates a right torque (right rotational force) according to the right motor driving signal L _R input from the motor control unit 130 and transmits it to the right gear 152 of the gear unit 150, and the left motor 144 generates a left torque (left rotational force) according to the left motor driving signal L _L input from the motor control unit 130 and transmits it to the left gear 154 of the gear unit 150.

Gear (150)

The gear unit 150 transmits the right gear 152 generated by the right motor 142 to the right lever 212 and the left torque generated by the left motor 144 to the left lever 214. It includes a left gear 154.

The right gear 152 is fixedly coupled to the rotation shaft of the right motor 142 as shown in FIG. 2 to transmit the right torque generated by the right motor 142 to the right lever 212 to rotate the rotation shaft. It includes a pinion gear (152A, Pinion Gear) that rotates according to and a rack member 152B having a sector shape fixedly coupled to the right lever.

A rack gear 52 is formed on the outer circumferential surface (a fan-shaped arc) of the rack member 152B, so that the rack gear 52 and the pinion gear 152A are engaged and the rack member 152B is rotated according to the rotation of the pinion gear 152A. Reciprocate back and forth.

That is, the right gear 152 has a rack-pinion gear structure, and transmits the right torque generated by the right motor 142 to the right lever 212 according to the rack-pinion gear structure.

The left gear 154 also has a rack-pinion gear structure like the right gear 152, and transmits the right torque generated by the left motor 144 to the left lever 214 according to this rack-pinion gear structure. The detailed structure of the left gear 154 is replaced by a description of the right gear 152.

As shown in FIGS. 5 and 7, the lever 210 is a right lever 212 and a left gear 154 whose positions are changed back and forth according to the back and forth reciprocating motion of the rack member 152B included in the right gear 152. ) And a left lever 214 whose position is changed back and forth according to the forward and backward reciprocating motion of the rack member included in ). As such, the lever 210 is mechanically (gear) connected to each motor for automatic operation, thereby enabling a system configuration for automatic operation.

The engine 220 may be a gasoline engine that provides driving power to the lawnmower according to the positions of the right lever 212 and the left lever 214.

For reference, if the left and right wheel speeds are the same, it goes straight, if there is a difference, it turns right or left, and if the sign is different, it becomes a spin (zero turn).

Sensor part (160)

The sensor unit 160 is mounted on the lawnmower and measures the actual speed and the actual posture angle of the lawnmower robot running according to the engine 220.

In order to measure the actual speed and the actual attitude angle, the sensor unit 160 is configured to include a plurality of sensors such as a radar sensor, a GPS sensor, a gyro sensor, and an acceleration sensor, and based on sensing values measured by each of the sensors. It is possible to measure the actual speed (v _m ) and the actual posture angle (θ _{m) of the driving lawnmower.}

Error Calculation (170)

_{The error calculation unit 170 calculates the difference between the actual speed (v m} ) input from the sensor unit 160 _{and the target speed (v t} ) input to the add/subtracter 110 to calculate a speed error (v _error). = v _m -v _t ) is generated, and the difference between the actual posture angle (θ _m ) input from the sensor unit 160 and the target posture angle (θ _t ) input to the add/subtracter 110 is calculated to calculate the posture angle error (θ _error). = θ _m -θ _t ) is generated and fed back to the adder and subtractor 110.

Then, the adder and subtractor 110 adds and subtracts the speed error (v _error ) and the posture angle error (θ _error ) to the target speed (v _t ) and the target posture angle (θ _t ), respectively, and the actual speed (v _m ) and the actual posture The error of the angle (θ _{m) is compensated.}

As such, the engine-driven lawn mowing robot 500 of the present invention includes an additive and subtractor 110, an integrated control unit 120, a motor control unit 130, a motor 140, a gear unit 150, a sensor unit 160, and an error. By mounting a control device including the calculation unit 170, automatic driving and automatic steering control of an engine-driven lawn mower operated by a conventional manual lever can be performed, so that the weeding operation can be performed by automatic operation, and a repetitive operation By performing the weeding operation by automatic operation in this required work space, it is possible to increase the user's convenience. Furthermore, it is possible to increase efficiency by configuring an automatic operation and automation system for various mechanical devices operated by levers.

10 is a flowchart illustrating a control method for automatic operation of an engine-driven lawn mower according to an embodiment of the present invention.

Referring to FIG. 10, first, in S610, the integrated control unit receives the bypassed target speed and target posture angle through an add/subtracter, and the left and right sides of the lawnmower from the input target speed and target posture angle. Calculate the wheel speed.

The calculation of the left and right wheel speeds may be calculated from the calculated turning radius, after calculating the turning radius of a lawn mower consisting of, for example, a drive wheel and a caster wheel, The calculation of the left and right wheel speeds ω _L and ω _R may be performed according to the execution of the program code in which Equations 1 to 5 are programmed.

The target speed and the target attitude angle may be pre-calculated before S610. For example, after installing a plurality of landmarks having a certain size at the corners of the work space, the lawn mower is positioned at a certain position inside and outside the work space. While rotating in place, the landmark is recognized through a sensor provided inside. Thereafter, a separate processor unit divides the work space at grid intervals according to the result of recognizing the landmark, and calculates an optimal travel path at the partitioned grid intervals. Then, the target speed and the target attitude angle are calculated for each grid interval partitioned from the calculated optimal travel path.

Subsequently, in S620, the motor control unit generates a left motor driving signal corresponding to a left lever position mapped to the left wheel speed input from the integrated control unit and a right motor driving signal corresponding to a right lever position mapped to the right wheel speed. Print it out.

Specifically, by referring to a lookup table representing the relationship between the left and right wheel speeds and the left and right lever positions, the left lever position mapped to the left wheel speed and the right lever position mapped to the right wheel speed are calculated, and the left lever position A left motor driving signal corresponding to and a right motor driving signal corresponding to the right lever position are output.

Subsequently, in S630, the left motor generates a left rotational force (left torque) according to the left motor driving signal, and the right motor generates a right rotational force (right torque) according to the right motor driving signal.

Subsequently, in S640, the left gear converts the left rotational force into reciprocating linear motion (back and forth reciprocating motion) and transmits it to the left lever, and the right gear converts the right rotational force into reciprocating linear motion and transmits it to the right lever.

Here, the left gear mechanically connects the left motor and the left lever according to the rack-pinion gear coupling method, as shown in Figs. 5 and 6, and similarly, the right gear is also the right gear according to the rack-pinion gear coupling method. Mechanically connect the motor and the right lever. According to such a rack-pinion gear coupling structure, the rotational force generated by the motor may be converted into a reciprocating linear motion (back and forth reciprocating motion) and transmitted to the lever.

Subsequently, in S650, the step of performing an automatic operation by the lawnmower according to the reciprocating linear motion of the left lever and the right lever.

After S650, a process of compensating for errors in the actual speed and the actual attitude angle according to the automatic driving may be further performed.

Specifically, after S650, after the sensor unit measures the actual speed and the actual attitude angle according to the automatic operation of the lawnmower, the error calculation unit calculates the difference between the actual speed and the target speed to generate a speed error. , A posture angle error is generated by calculating a difference between the actual posture angle and the target posture angle. Thereafter, an addition/subtracter provided at the front end of the integrated control unit compensates for the error between the actual speed and the actual posture angle by adding and subtracting the speed error and the posture angle error to the target speed and the target posture angle, respectively.

Above, the present invention has been described centering on the embodiments, but these are only examples and do not limit the present invention, and those of ordinary skill in the field to which the present invention pertains will not depart from the essential characteristics of the present invention. It will be appreciated that various modifications and applications that are not illustrated in are possible. For example, each component specifically shown in the embodiment of the present invention can be modified and implemented. And differences related to these modifications and applications should be construed as being included in the scope of the present invention defined in the appended claims.

Claims (16)

In the driving method of an unmanned lawnmower robot capable of autonomous driving,
Obtaining, by a radar sensor, a distance value and an angle value from a reflected signal of a radar signal transmitted to a landmark defining a working space;
Obtaining an image by photographing the landmark by a camera sensor;
The path calculation unit corrects the angle value from the distance value and the angle value input from the radar sensor using the image input from the camera sensor, and uses the distance value and the corrected angle value to the work space. Calculating a driving route within the vehicle; And
Driving, by a driving device, the unmanned lawn mower robot according to the calculated travel path.
Driving method of an unmanned lawn mower robot comprising a. In claim 1,
The driving method of the unmanned lawnmower robot further comprising the step of setting the work space using the image obtained by the camera sensor photographing the landmark by the path calculation unit. In paragraph 2,
The step of setting the working space,
Based on the relationship between the size of the landmark in the image defined in advance and the distance from the unmanned lawnmower to the landmark, the work space is calculated based on the size of the landmark included in the image currently input from the camera sensor. How to drive the unmanned lawnmower robot that is set by. In claim 1,
The step of calculating the travel path,
Searching for a center point of the landmark on the image and correcting the angle value using coordinate information of the searched center point
Driving method of an unmanned lawn mower robot comprising a. In claim 1,
The step of calculating the travel path,
Converting the distance value and the angle value into UV coordinates;
Searching for a center point of the landmark based on the converted UV coordinates on the image; And
Calculating a difference value between the UV coordinate corresponding to the searched center point and the converted UV coordinate, and correcting the angle value using the calculated difference value
Driving method of an unmanned lawn mower robot comprising a. A route calculation device for calculating a travel path and a driving device for driving autonomous driving of the unmanned lawnmower robot according to the calculated travel path,
The route calculation device,
A radar sensor that obtains a distance value and an angle value from a reflected signal of a radar signal transmitted to a landmark defining a working space;
A camera sensor that captures the landmark and acquires an image; And
Among the distance values and angle values input from the radar sensor, the angle value is corrected using the image input from the camera sensor, and the distance value and the corrected angle value are used in the working space. Route calculation unit that calculates the driving route
Unmanned lawn mower robot comprising a. In paragraph 6,
The path calculation unit,
The unmanned lawn mower robot to set the working space using the image acquired by the camera sensor photographing the landmark. In paragraph 6,
The path calculation unit,
Based on the relationship between the size of the landmark in the image defined in advance and the distance from the unmanned lawnmower to the landmark, the working space is determined based on the size of the landmark included in the image currently input from the camera sensor. An unmanned lawnmower robot that calculates and sets. In paragraph 6,
The path calculation unit,
An unmanned lawn mower robot that searches for a center point of the landmark on the image and corrects the angle value using coordinate information of the searched center point. In paragraph 6,
The path calculation unit,
The difference between the UV coordinates corresponding to the searched center point and the converted UV coordinates by converting the distance value and angle value to UV coordinates and searching for the center point of the landmark based on the converted UV coordinates on the image The unmanned lawn mower robot to correct the angle value using the value. In the route setting method of an unmanned lawnmower capable of autonomous driving,
Obtaining, by the radar sensor, a distance value and an angle value from the reflected signal of the radar signal transmitted to the landmark;
Obtaining an image by photographing the landmark by a camera sensor;
Correcting, by a path calculator, the angle value using the image;
Selecting, by the route calculator, a target landmark from among a plurality of landmarks based on the distance value and the corrected angle value;
Generating, by the route calculator, a traveling route following the selected target landmark; And
Calculating, by the route calculating unit, a target speed value and a target attitude angle corresponding to the traveling route
Route setting method of the unmanned lawnmower robot comprising a. In clause 11,
Prior to the step of obtaining the distance value and angle value,
Setting a work space using an image obtained by photographing a landmark by the camera sensor, by the route calculation unit; And
The path calculation unit dividing the set working space into a grid interval of a unit smaller than the weeding width of the unmanned lawn mower robot
Route setting method of the unmanned lawnmower robot comprising a. In claim 12,
The step of setting the working space,
Based on the relationship between the size of the landmark in the image defined in advance and the distance from the unmanned lawnmower to the landmark, the work space is calculated based on the size of the landmark included in the image currently input from the camera sensor. How to set the path of the unmanned lawnmower robot that is set by using. In clause 11,
The step of correcting,
Converting the distance value and the angle value into UV coordinates;
Searching for a center point of the landmark based on the converted UV coordinates on the image; And
And calculating a difference value between the UV coordinate corresponding to the searched center point and the converted UV coordinate, and correcting the angle value using the calculated difference value. In clause 11,
The step of selecting the target landmark,
The method of setting a route of the unmanned lawnmower robot further comprising the step of assigning a track ID to the selected target landmark. In clause 11,
After the step of calculating the target speed value and the target attitude angle, determining whether the target landmark is changed,
The determining step,
The difference between the distance value previously acquired by the radar sensor and the current acquired distance value and the first threshold are compared, and the angle value corrected for the angle value previously acquired by the radar sensor and the current acquired angle value from the radar sensor are compared. The route setting method of the unmanned lawnmower robot, wherein the difference value between the corrected angle value and the second threshold value are compared to determine whether or not the target landmark is changed.

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