JP2916320B2 - Travel control method for unmanned lawn mower - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a running control method for an unmanned lawn mower.

[0002]

2. Description of the Related Art As a conventional traveling control system of an automatic guided vehicle, an electromagnetic induction system is employed. There is no electromagnetic induction type unmanned lawn mower, but if this is applied to an unmanned lawn mower, it is necessary to lay an induction wire on the lawn and detect the electromagnetic waves generated from the induction wire by the unmanned lawn mower. Become. As a prior art, there is JP-A-2-193202.

[0003]

In the above-mentioned electromagnetic conduction system,
Since the induction wires need to be buried underground, the turf must be dug up, damaging the turf and taking time to recover.
In order to mow the lawn completely, the induction wires must be densely laid, which requires a great deal of labor and cost. In addition, since the traveling route is fixed, the unmanned lawn mower always travels on the same route,
A rut is created.

[0004]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the invention according to claim 1 of the present application comprises mounting an azimuth sensor and a distance sensor on an unmanned lawn mower and a cruise control device. The storage device stores a planar map that is divided into a large number of unit elements in a checkerboard pattern by the X-axis and Y-axis division lines. While cutting the boundary line, teaching the closed curve corresponding to the boundary line on the map, converting the unit element located on the closed curve to another state, placing the lawn mower within the boundary, and traveling direction at the current position On the other hand, the left and right one side, the front side and the left and right other side unit elements are sequentially determined, and if the left and right one side unit elements are not in the cut state, the process proceeds to the one side unit element, and the one side unit element. Unit element is reaped If the unit element on the front side has not been pruned yet, the process proceeds to the unit element on the front side, and if the unit element on one side and the unit element on the front side have already been pruned and the unit element on the other side has not been pruned, the other side Mowing work by controlling the running of each unit element so as to advance to the unit element of the unit, and automatically running only the portion corresponding to the unconverted unit element, sequentially converting the unit elements in the closed curve of the map into a turning shape I do.

According to the second aspect of the present invention, in order to further improve the work efficiency, the unmanned lawn mower is equipped with a direction sensor and a distance sensor and a travel control device. The apparatus stores a planar map divided into a large number of unit elements in a grid pattern by the X-axis and Y-axis division lines, and converts the unit elements corresponding to the boundaries of the predetermined area on the map in advance. Putting the unmanned lawn mower on the non-conversion unit element in the boundary, the left and right one side, the front side and the left and right other side are sequentially determined with respect to the traveling direction at the current position, and the left and right one side. If the unit element of the uncut state, proceed to the unit element on one side, if the unit element of the one side has been cut and the unit element on the front side is uncut state, proceed to the unit element on the front side, one side The unit element of If the elements have also been pruned and the other unit element is not pruned, the traveling control is performed for each unit element so as to proceed to the other unit element, and only the portion corresponding to the unconverted unit element is automatically driven. Thus, the lawn mowing operation is performed while sequentially converting the unit elements of the map into a turning shape.

[0006]

First, an example of a self-propelled unmanned lawnmower controlled by the control method of the present invention will be described. FIG. 1 is a plan view showing a three-wheel type unmanned lawn mower in a partial cross section. A box-shaped body 1 is provided with running wheels 2 at a front portion so as to be steerable, and a pair of right and left at a rear portion. A rear wheel 3 is provided for driving. Inside the body 1, a longitudinal axis engine 5 is provided in the center, a battery 7 is provided on the side of the engine, and a control device 8 is provided behind the engine.

In FIG. 2, a cutting blade 20 is connected to a power take-out shaft 17 extending below the engine 5. A steering gear transmission mechanism 15 and a steering motor 21 are attached to the front traveling wheel 2, and the rotation of the steering motor 21 allows the traveling wheel 2 to be steered in the left-right direction via the gear transmission mechanism 15. ing. The rear wheel 3 is linked to the engine 5 via a power transmission mechanism (not shown).

An azimuth sensor 29 using a gyro compass or the like is provided on the upper part of the body 1, and a distance sensor 30 for detecting the travel distance of the body is provided on the traveling wheels 2, and the azimuth and the integration are respectively obtained therefrom. It is connected to the control device 8 so as to input a distance input signal to the control device 8.

A storage device in the control device 8 stores a map divided into a number of unit elements in a grid pattern in the vertical and horizontal directions, that is, on the X axis and the Y axis as shown in FIG. For example, E of 16Kbyte S-RAM (with backup)
When CU is used, 16 × 1024 × 8 = 131
A map is obtained which is divided into unit elements of 072 = 362 × 362 bits.

In this map, in the initial state, each unit element is either "0" (off) or "1" (on).
The state is set to “0”.

At the start of the work, a base position G is first determined on the lawn of FIG. 3, which is recognized on the map of FIG. 4, and initialized at this position. Therefore, the azimuth and the distance are measured based on the base position G, and are input to the control device 8. In FIG. 3,
H indicates a house and T indicates a tree.

Next, for example, as shown in FIG.
Alternatively, the lawn mower M is placed at a position where the relative position with respect to the lawn mower M is determined, and the lawn mower M is manually driven.
, The corresponding unit elements on the map are sequentially converted to “1”. The unit element indicated by diagonal lines has been converted to the state of “1”, and the corresponding lawn has been cut off, while the unit element indicated by the outline remains in the state of “0” and has not been changed. It is in a cutting state.

Then, finally, as shown in FIG.
Around the perimeter of the desired area to be cut away by the manual operation, avoiding obstacles such as the tree T and the tree T, a closed curve corresponding to the boundary of the desired area is drawn on the map as shown in FIG. Each unit element on the closed curve is converted from “0” to “1”. In the operation of drawing the closed curve (boundary line), the distance sensor 29 is used with the base point G as the origin.
The azimuth sensor 30 detects the distance and azimuth from the base position G, calculates the coordinates of the boundary on the map, and sequentially converts the unit elements corresponding to the boundary.

Next, as shown in FIG. 9, the unmanned lawn mower is placed along the boundary within the above-described teaching, along the boundary, and automatically travels, and travels only at the location corresponding to the unit element in the "0" state. Thus, the unit elements in the “0” state are sequentially converted to the “1” state, and the automatic traveling is terminated when the unit elements in the “0” state disappear.

As a method for converting the unit element corresponding to the boundary line from "0" to "1" without fail, for example, as shown in FIG. 11, with respect to the traveling direction B at the current position P1, Left side (A side), front side (B side) and right side (C side)
The states of the unit elements are determined in order.If the left side is uncut, the vehicle moves forward.If the left side is already cut and the front side is uncut, it moves forward, the left side and the front side are also cut, and the right side is not cut. A control method is adopted in which the vehicle moves to the right in the state, and stops if the left side, the front side, and the right side have been mowed.

More specifically, as shown in the flowchart of FIG. 13, first, in step 1, it is determined whether or not the unit element on the left side (A side) is "1". Is determined to be “0” (non-pruned state), the process proceeds to step 2, the vehicle proceeds to the left, enters the left unit element, and cuts a portion corresponding to the left unit element, thereby obtaining “ 1 ", and returns to step 1. On the other hand, if YES in step 1, that is, if the left unit element is “1” (having been cut), the process proceeds to step 3, and it is determined whether the front unit element is “1”. If NO, the front side is determined to be in the state of "0" (uncut state), and the process proceeds to step 4 to advance and enter the front-side unit element, and a position corresponding to the front-side unit element is determined. This is converted to "1" by cutting, and the process returns to step 1. On the other hand, in step 3,
In the case of YES, that is, when the front unit element is “1”, the process proceeds to step 5, where it is determined whether the right unit element is “1”. It is determined that the state is "0" (non-pruned state), and the process proceeds to step 6, goes right, enters the right unit element, and cuts a portion corresponding to the right unit element to "1". And returns to step 1. In step 5, if YES, that is, if the unit element on the right side is "1", the process proceeds to step 7, and the lawnmower stops. This finishes the lawn mowing work.

By the way, in the case as shown in FIG. 12, the lawn mower moves rightward from the position P1, moves to a position corresponding to the unit element (C) on the right side, and then advances again at the position (C). Left (A1), front (B1) and right (C1) to the direction
The states of the unit elements are sequentially determined, and the vehicle advances leftward to A1.

In the case where the control according to the so-called left-hand rule shown in FIGS. 11 to 13 is employed, after cutting the boundary, the lawn mower M is arranged along the boundary as shown in FIG. 9, that is, at the outer end. If the lawn mower M is arranged in the center after the boundary has been cut,
While turning to the left, the vehicle runs from the center to the outside.

While the vehicle is traveling in the area, the boundary line is not linear, but has a width corresponding to the cutting width. Therefore, the traveling error can be absorbed to some extent by the width of the boundary line.

In the case of a garden having a complicated shape, the garden can be divided into several blocks, each block is surrounded by a boundary line, and lawn mowing work can be performed for each block. In this way, there is an advantage that the lawn mowing operation can be easily performed even in a garden having a complicated shape, and the work can be divided.

[0021]

[0022]

FIG. 14 shows a control method to which the invention according to claim 2 is applied. A layout corresponding to a lawn such as a garden shown in FIG. For example, the unit elements corresponding to the house H, the tree T, the side of the garden, and the like are set and set to the state of “1”. Then, the lawn mower is set at any position corresponding to the unit element in the “0” state, and the lawn mower is automatically driven. The running control of the lawn mower is the same as that of the first embodiment. The data of the default map is processed by a personal computer, and is communicated to the ECU of the control device in the lawn mower by RS232C or the like and stored. If an IC memory is used, the memory can be shared between the personal computer and the ECU, and a communication circuit becomes unnecessary. If the map and the lawn mowing operation do not match when actually running, the computer corrects the map. That is, the personal computer software has the map editor function, file management function, and communication function.

[0023]

As described above, according to the present invention,
By sequentially converting the unit elements of the map stored in advance, control is performed so that the lawn in a predetermined range is completely cut off.Therefore, it is necessary to embed electric wires etc. in the lawn compared to the case where the electromagnetic induction method is adopted. As a result, the lawn mower does not always run on the same route to form a rut, so that the lawn is not damaged and equipment costs can be reduced. According to the first aspect of the present invention, the reaping area can be freely set, so that even a lawn having a complicated shape can be divided into an appropriate shape having an appropriate size, and the reaping operation can be easily performed. It can be carried out. In addition, even if there is some error when adjusting the distance sensor or the direction sensor, the error when cutting the border first, and the error when performing the tasting will be the same when running inside the boundary afterwards. , The above-mentioned errors are offset, and the control of the cutting range can be performed with high accuracy. According to the second aspect of the present invention, it is not necessary to first perform a manual operation for setting a boundary line, thereby improving work efficiency. Further, in any of the inventions described above, the position of the lawn mower is determined for each of the unit elements divided in a grid pattern, and the next unit element is moved to the next unit element while determining the next unit element. It is a control, and furthermore, the states of the unit elements are determined in the order of the left, front and right sides (or the reverse order), and according to the rule of the left hand (or the rule of the right hand),
The unit elements to be advanced in the above priority order are determined, and the vehicle travels in a swirling shape within the boundary, so that even on grassy land where it is difficult to maintain straight traveling performance in a large area, it is possible to mow the area without leaving uncut areas. It is.

[Brief description of the drawings]

FIG. 1 is a horizontal sectional view of an unmanned lawn mower used in a guidance method according to the present invention.

FIG. 2 is a longitudinal sectional view of the unmanned lawn mower.

FIG. 3 is a plan view showing an example of a lawn.

FIG. 4 is a schematic diagram showing a state of a map before work.

FIG. 5 is a plan view of a lawn showing a state at the start of work according to the first aspect of the present invention.

FIG. 6 is a schematic diagram of a map corresponding to the state of FIG. 5;

FIG. 7 is a plan view of a lawn at the end of teaching.

FIG. 8 is a schematic diagram of a map corresponding to the state of FIG. 7;

FIG. 9 is a plan view of a lawn during a lawn mowing operation within a boundary line.

FIG. 10 is a schematic diagram of a map corresponding to the state of FIG. 9;

FIG. 11 is an enlarged schematic diagram of a map showing a lawn mower traveling control method.

FIG. 12 is an enlarged schematic diagram of a map showing a specific example of a lawn mower traveling control method.

FIG. 13 is a flowchart of a lawn mower traveling control method.

FIG. 14 is a schematic diagram showing a state of a map at the time of starting work according to the second aspect of the present invention.

[Explanation of symbols]

 M Unmanned lawn mower 29 Direction sensor 30 Distance sensor

Claims (2)

(57) [Claims] An unmanned lawn mower is equipped with a direction sensor and a distance sensor and a travel control device, and a storage device in the travel control device has a large number of units in a checkerboard pattern by X-axis and Y-axis division lines. By storing a planar map divided into elements, and moving the lawn mower around the periphery of a predetermined area, the boundary of the area is cut, and a closed curve corresponding to the boundary is taught on the map. Then, convert the unit element located on the closed curve to another state, place the lawn mower within the boundary, and sequentially move the unit element on one side on the left, right side, front side and the other side on the left and right with respect to the traveling direction at the current position. If it is determined that one of the left and right unit elements is in the uncut state, the process proceeds to the one unit element.If the one of the unit elements is already cut and the front unit element is in the uncut state, the front side is uncut. Unit element If the unit element on one side and the unit element on the front side have already been pruned and the unit element on the other side has not been pruned, the traveling control is performed for each unit element so as to proceed to the unit element on the other side, and non-conversion is performed. A lawn control method for an unmanned lawn mower characterized in that a lawn mowing operation is performed while sequentially converting the unit elements in a closed curve of a map into a swirling shape by automatically running only a portion corresponding to the unit element of (1). 2. An unmanned lawn mower is equipped with a direction sensor and a distance sensor and a travel control device, and a storage device in the travel control device has a large number of units in a checkerboard pattern by X-axis and Y-axis division lines. A planar map divided into elements is stored, unit elements corresponding to boundaries of a predetermined area are previously converted on the map, and an unmanned lawn mower is placed on a non-converted unit element within the boundary. For the traveling direction at the position, one side on the left and right, the front side and the unit element on the other side on the left and right are sequentially determined, and if the unit element on the left and right sides is uncut, the process proceeds to the unit element on the one side, If the one unit element has been pruned and the front unit element has not been pruned, the process proceeds to the front unit element, and both the one unit element and the front unit element have been pruned and the other unit element has not been pruned. If you are in a reaping state, Running control is performed for each unit element so as to proceed to the unit element on the other side, and only parts corresponding to unconverted unit elements are automatically driven, so that lawn mowing work can be performed while sequentially converting the unit elements of the map into a turning shape. A driving control method for an unmanned lawn mower, wherein the method is terminated.