JP3632618B2 - Mobile work robot - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a mobile work robot that automatically performs work such as an automatic floor cleaner, an automatic floor finisher, and the like.
[0002]
[Prior art]
In recent years, various mobile work robots have been developed that perform work automatically by adding a travel drive device, sensors, travel control means, and the like to the work equipment. For example, a self-propelled cleaner is provided with a suction nozzle, a brush or the like at the bottom of the main body as a cleaning function, and an obstacle detection means for detecting an obstacle during traveling and steering means and an obstacle as a moving function, and a position recognition means for recognizing the position. And moving along the wall around the cleaning place by the obstacle detection means, recognizing the cleaning area by the position recognition means, and moving in the cleaning area to clean the entire cleaning area. is there.
[0003]
Here, the influence by the carpet eyes related to the self-propelled cleaner will be described with reference to FIG. If the floor of the work area is a carpet with a strong carpet, such as a cut-pile carpet with a long bristle, and the carpet is in a direction perpendicular to the straight direction, the body gradually moves while driving. The phenomenon of flowing in the eye direction occurs. In FIG. 10, (1) shows the movement trajectory of the main body 11 when going straight on a flat bare floor without a carpet. At this time, since there is no carpet, there is no influence of the carpet, and the movement trajectory of the main body 11 is a straight line a that matches the direction of the main body at the start of traveling. However, for example, as shown in (2), if the floor surface is changed to a carpet with the carpet eyes in the direction from left to right, and the vehicle goes straight under the same conditions, the main body performs straight-ahead control so as to ride on the target line L1. The movement trajectory is a straight line b that is inclined rightward from the direction of the target line L1 by an angle θ, although the main body always faces the direction at the start of traveling. The angle deviation θ indicating the degree of lateral deviation is almost unique to the carpet and is about several degrees.
[0004]
[Problems to be solved by the invention]
However, in the mobile work robot having the above-mentioned conventional cleaning function, the angle deviation of the lateral deviation due to the carpet is checked in advance and the remaining work or work is not performed unless the information is artificially given from the outside and incorporated into the control. A decrease in efficiency occurs. In addition, this information cannot be dealt with when a time-dependent change occurs in the carpet or when the carpet is relaid.
[0005]
Accordingly, an object of the present invention is to provide a mobile work robot that can automatically detect an angular deviation of a lateral deviation due to a carpet.
[0006]
[Means for Solving the Problems]
In order to solve the above-described conventional problems, a mobile work robot according to the present invention includes a driving means including a driving wheel for moving a main body and a driving motor for driving the driving wheel, a support shaft and a wheel that are rotatable with respect to the main body. A steering means comprising: a driving control means for controlling the driving means and the steering means to control the driving of the main body; a direction measuring means for measuring the direction of the main body; and a distance from the main body to an external object. Distance measurement means, obstacle detection means for detecting an obstacle based on the output of the distance measurement sensor, turning means for turning the traveling direction of the main body by 180 ° by the output of the obstacle detection means, and the rotation angle of the support shaft an angle detecting means for detecting comprises a working unit for performing operations, said running control means may be straight body target direction based on the output of the direction measuring means, the angle detecting means to the target direction of the straight Is straight subjected to modification on the basis of the force angle, and the obstacle detection means pivoting means operates in the angle detection means with the the turning means for detecting an obstacle to straight After 180 ° turning the traveling direction of the body And the angle detecting means is stopped until the vehicle travels straight after the turning means is operated, and the steering means includes a wheel, a wheel shaft that rotatably supports the wheel, and the wheel shaft. A wheel shaft holding portion that is supported from both sides, a support shaft fixing member that urges the wheel shaft from the upper side and both sides inside the wheel shaft holding portion, and a support shaft that connects the support shaft fixing member to the angle detection means. It is configured.
[0007]
This makes it possible to detect the direction and strength of the carpet according to the rotation angle of the support shaft, and to make a straight run that corrects the influence of the carpet , and to prevent the rotation of the wheel during turning from being included in the detection of the carpet. In addition, since the angle detecting means is stopped until the straight traveling is stably performed after the turning means is operated, the accuracy of detecting the carpet can be improved.
[0008]
DETAILED DESCRIPTION OF THE INVENTION
According to a first aspect of the present invention, a mobile work robot according to the present invention includes a driving means including a driving wheel for moving a main body, a driving motor for driving the driving wheel, a support shaft and a wheel that are rotatable with respect to the main body. Steering means, a driving control means for controlling the driving of the main body by controlling the driving means and the steering means, a direction measuring means for measuring the direction of the main body, and a measurement for measuring the distance from the main body to an external object. Distance means, obstacle detection means for detecting an obstacle based on the output of the distance measuring sensor, turning means for turning the traveling direction of the main body by 180 ° by the output of the obstacle detection means, and the rotation angle of the support shaft comprising a detection angle detecting means, a work unit for performing work, the travel control means may be straight body target direction based on the output of the direction measuring means, the output angle of the angle detection unit to the target direction of the straight Is straight subjected to modification based, and turning means operate with linearly moving after the has a pivoting mechanism obstacle detecting means detects an obstacle was 180 ° turning the traveling direction of the body stops the angle detection means In addition, the angle detecting means is stopped until the vehicle travels straight after the turning means, and the steering means supports the wheel, the wheel shaft that rotatably supports the wheel, and the wheel shaft from both sides. A wheel shaft holding portion, a support shaft fixing member that urges the wheel shaft from the upper side and both sides inside the wheel shaft holding portion, and a support shaft that connects the support shaft fixing member to the angle detection means. In addition, since the angular deviation of the lateral deviation due to the carpet is automatically detected and corrected, it is possible to realize a mobile work robot that can perform work without causing any unfinished work or lowering work efficiency.
[0009]
According to the second aspect of the present invention, since the support shaft and the angle detecting means are directly connected, and the configuration such as the coupling for absorbing the impact is unnecessary, the angle detection of the wheel can be realized with a compact configuration.
[0010]
According to a third aspect of the present invention, the support shaft fixing member is made of an elastic material, and the rotation of the wheel is reliably transmitted to the support shaft and reliably detected by the angle detection means, thereby improving the accuracy of the carpet eye detection. Even when an upward external force is applied to the wheel due to a step, an obstacle, etc., it is absorbed by the elastic force and can absorb the impact on the angle detection means.
[0011]
According to a fourth aspect of the invention, the steering means and the angle detecting means intended to be removable from the main body integrally, it is possible to facilitate the maintenance of the parts such as replacement of the steering means.
[0012]
According to the fifth aspect of the present invention, the wheels are arranged behind the drive wheels, and the detection sensitivity of the carpet sensor can be improved.
[0013]
The invention according to claim 6 has the center of gravity of the main body in the vicinity of the wheel, and can improve the detection sensitivity of the carpet sensor.
[0014]
【Example】
(Example 1)
Hereinafter, the case where the embodiment of the present invention is applied to a self-propelled cleaner will be described as an example with reference to FIGS.
[0015]
FIG. 1 is a cross-sectional view showing the overall configuration of the self-propelled cleaner of this embodiment, FIG. 2 is a cross-sectional view showing the configuration of the driving and steering means of this embodiment, and FIG. 3 is a side cross-sectional view showing the configuration of the steering means. 4 is a front sectional view showing the structure of the steering means, and FIG. 5 is an internal perspective view showing the arrangement of the distance measuring sensor and the direction measuring means. In the figure, 11 is a main body of the self-propelled cleaner, and 12L and 12R are drive wheels provided on the left and right rear sides of the main body 11, respectively, and are independently driven left and right by the drive motors 13L and 13R. Reference numerals 14L and 14R are rotation detectors composed of a rotary encoder or the like connected to 13L and 13R, respectively, and detect the shaft rotational speeds of the drive motors 13L and 13R. Reference numeral 15 denotes steering means for supporting the weight of the main body 11, and the wheel 16 is rotatably attached to the wheel shaft holding portion 18 via the wheel shaft 17. As described above, the main body 11 is moved by the driving means and the steering means 15 including the driving wheels 12L and 12R and the driving motors 13L and 13R.
[0016]
Reference numeral 19 denotes a rotation support portion (bearing) that supports the wheel shaft holding portion so as to be rotatable in the horizontal direction. Reference numeral 21 denotes a support shaft fixing member that supports the wheel 16. The support shaft fixing member 21 can move the wheel shaft 17 in the vertical direction and supports the wheel shaft 17 from both sides. The wheel shaft 17 is urged on both sides and is directly fixed to the angle detection means 22 by the support shaft 20. The angle detection means 22 comprising a rotary encoder or a potentiometer fixed on the angle detection means holding plate 23 detects the rotation of the support shaft 20, whereby the rotation angle of the wheel shaft holding portion 18 is determined. Detect. Since the support shaft fixing member 21 is formed of a spring material such as stainless steel, the wheel shaft holding portion 18 is urged upward and outward, so that even if the wheel shaft holding portion 18 is slightly rotated. It can be accurately transmitted to the angle detection means 22 via the shaft 20.
[0017]
Further, since the support shaft fixing member 21 is configured to bend with respect to an upward force, it is supported even if an upward force is applied to the wheel 16 and the wheel shaft 17 due to an external factor (an obstacle such as a convex step). Since the shaft fixing member 21 absorbs, no impact is directly applied to the angle detection means 22. As a result, the coupling between the support shaft 20 and the angle detection means 22 can be directly coupled without requiring a coupling for absorbing an impact, and the size of the angle detection means can be reduced.
[0018]
Steering means 15 (comprising wheel 16, wheel shaft 17, wheel shaft holding section 18, rotation support section 19, support shaft 20, support shaft fixing member 21) and angle detection means 22 are fixed to angle detection means holding plate 23. After that, since it is configured to be attached to the main body 11, maintenance inspection and part replacement of the steering means 15 and the angle detection means 22 can be performed simply by removing the angle detection means holding plate 23 from the main body 11.
[0019]
The drive wheels 12L and 12R and the drive motors 13L and 13R are arranged near the center of the main body, and the steering means 15 is provided behind the drive wheels 12L and 12R, and a rechargeable battery 24 that supplies electric power to the whole is provided. Since it is disposed above the steering means 15, the entire center of gravity 25 is in the vicinity of the steering means 15. For this reason, the wheel 16 of the steering means 15 is easy to receive the force from a carpet, and the sensitivity of an angle detection means improves.
[0020]
26 is an electric blower, 27 is provided at the bottom of the main body 11, and is a suction portion which is a working means for performing cleaning work by sucking dust on the floor surface by the suction force generated by the electric blower 26. Connected to a dust collection chamber (not shown). Reference numeral 30 denotes direction measuring means for measuring the direction of the main body 11, and includes a gyro and an integrator for integrating the output. 31 is a distance measuring sensor consisting of an ultrasonic sensor or the like provided around the main body 11, the front of the main body 11, left and right sides and the obstacle detecting an obstacle by measuring the distance to an object located behind detection Intellectual Means. Reference numeral 32 denotes a travel control means for controlling the drive motors 13L and 13R based on data from the direction measuring means 30 and the obstacle detection means 31 to control the travel of the main body.
[0021]
FIG. 6 is a control block diagram of this embodiment. The direction measuring means 30, the distance measuring sensor 31, the rotation detector 14 and the angle detecting means 15 input their outputs to the traveling control means 32. The traveling control means 32 judges these data and outputs a control signal to the drive motors 13L and 13R. In this embodiment, the rotational speeds of the drive motors 13L and 13R are controlled to independently control the rotational speeds of the left and right drive wheels 12L and 12R, thereby driving and steering the main body 11.
[0022]
Now, the influence of the carpet when traveling straight on the carpet will be described with reference to FIG. In the figure, (1) shows the movement trajectory of the main body 11 when the traveling floor is a bare floor without a carpet. As described in the prior art, since there is no carpet at this time, there is naturally no influence of the carpet, and the main body 11 performs straight-ahead control by the straight-ahead means of the travel control means 32, and the movement trajectory of the main body 11 at the start of travel is It becomes a straight line a that coincides with the direction. However, for example, as shown in (2), when the floor surface is changed to a carpet whose carpet is in the direction from left to right, and the vehicle travels straight under the same conditions, the main body 11 is a straight traveling mode that the traveling control means 32 has. However, the actual movement trajectory is inclined to the right by the angle θ from the direction of the target line L1 despite the fact that the main body 11 always faces the direction at the start of traveling. A straight line b is obtained. That is, the present inventors have found that when the main body 11 travels straight on the carpet, the main body 11 slides in the direction of the carpet in proportion to the rectilinear distance of the main body 11, and represents the degree of this side slip. It is confirmed that the angle deviation θ is almost unique depending on the carpet and is about several degrees. Therefore, for example, as shown in FIG. 7 (3), the straight line L2 is defined as a straight line L2 inclined at an angle θ to the left from the direction at the start of traveling on the carpet in which the angle deviation θ is measured in advance during the first traveling. When the vehicle travels straight under the same conditions, the movement locus at that time becomes a straight line c that coincides with the direction of the main body 11 at the start of traveling. Similarly, as shown in (4), when the vehicle travels straight in the direction opposite to (3), the target line of the straight traveling means is set to L3 inclined at an angle θ to the right from the direction at the start of travel. By doing so, the movement locus becomes a straight line d that coincides with the direction of the main body 11 at the start of traveling. As described above, when the vehicle travels straight on the carpet, it is known that the movement trajectory of the main body 11 can be corrected by changing the direction of the target line of the straight traveling means in accordance with the direction of the carpet and the strength of the eyes.
[0023]
Further, the wheel 16 of the steering means 15 of the carpet eye detection means is supported by the wheel shaft holding portion 18 and the rotation support portion 19 so as to be rotatable in the horizontal direction with respect to the main body 11, so that the main body 11 always travels. It will turn in the direction of travel. That is, in the example of (1) of FIG. 7, the wheel 16 faces the direction of the straight line a, and in the example of (2), the wheel 16 faces the direction of the straight line b.
[0024]
FIG. 8 is a flowchart showing a control method in the traveling control means 32 of this embodiment. Reference numeral 34 denotes carpet displacement calculation means for calculating the average angle of the output of the angle detection means 22. Reference numeral 35 denotes a travel correction unit that inputs the value of the carpet deviation calculation unit 34 and sets a correction target line for straight-ahead control. Reference numeral 36 denotes a driving motor based on the direction data of the main body 11 measured by the direction measuring means 30 and the outputs of the rotation detectors 14L and 14R so that the main body 11 gets on the correction target line set by the travel correction means 35. It is a straight traveling means for controlling 13L and 13R to travel straight ahead. Further, an obstacle is detected in front of the main body 11 by a distance measuring sensor during straight traveling, and if the cleaning operation is not completed, the position is reversed to a position displaced in the work direction by a predetermined work width.
[0025]
The movement locus of the self-propelled cleaner will be described with reference to FIG. It is assumed that the floor surface to be cleaned by the main body 11 has carpet eyes from left to right. When the main body 11 is started at the start point S, the vehicle 11 starts to travel straight, and as in the case of (2) in FIG. Will be swept to the right due to the carpet. As already described, the wheel 16 of the carpet detection means is supported by the wheel shaft holding portion 18 and the rotation support portion 19 so as to be rotatable in the horizontal direction with respect to the main body 11. Turn to the direction. When the obstacle detection means 31 approaches the front wall W1 and detects this, it is checked whether there is an obstacle in the direction of the working direction A. In this case, since there is no obstacle, the direction measuring means 30 is used to invert exactly 180 ° at a position displaced by a predetermined working width in the working direction A, that is, to the right of the body 11 at the point P1. At this time, the carpet deviation calculation means 34 calculates the average value θ1 of the output angle of the angle detection means 22 until the inversion starts at the point P1. After the inversion at the point P1, based on this calculation result, the travel correction means 35 sets a correction target line (a straight line inclined to the right of the main body 11 by the angle θ1), and the straight movement means 36 sets the main body 11 to the target line. Perform straight-ahead control to get on. When the straight-ahead control is started and the output of the direction measuring means is stabilized, the carpet deviation calculating means 34 newly calculates the average value θ2 of the output angle of the angle detecting means until it is turned 180 ° at the point P2 approaching the wall W2. After inversion at the point P2, based on the calculation result, the traveling direction correcting means 35 sets a correction target line (a straight line inclined by the angle θ2 to the left of the main body 11), and the straight traveling means 36 makes the main body 11 the target line. Perform straight-ahead control to get on.
[0026]
When the above operation is repeated and the wall W2 is detected in front of the main body 11 at the point F, the wall W3 is present in the working direction A, that is, in the right direction of the main body 11, so that it is determined that the cleaning is finished and the work is finished. .
[0027]
The carpet displacement calculation means 34 does not use the output of the angle detection means 22 when the main body 11 detects a wall (or an obstacle) and reverses 180 ° and when the wheel 16 after the reverse is not facing the traveling direction. Since the displacement due to the carpet eyes is calculated, the influence due to the carpet eyes can be accurately corrected.
[0028]
As described above, according to this embodiment, the direction of the steering means 15 relative to the main body 11 of the wheel 16 is detected by the angle detection means 22 via the rotation support portion 19, and the deviation angle due to the carpet is calculated by the carpet deviation calculation means 34. On the basis of this calculation result, the travel correction means 35 sets the target line for straight-ahead control as the correction target line and performs straight-ahead control. Therefore, the reciprocal straight-ahead trajectory of the main body 11 becomes parallel, and the working width changes during travel. Therefore, there is no possibility of leaving uncleaned or reducing cleaning efficiency.
[0029]
【The invention's effect】
According to the present invention, it is possible to automatically detect a lateral deviation angle deviation due to a carpet, and it is possible to realize a mobile work robot that can prevent uncleaning and cleaning efficiency from being lowered.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view of a self-propelled vacuum cleaner showing a first embodiment of the present invention. FIG. 2 is a cross-sectional view showing the structure of the drive and steering means. FIG. 4 is a front sectional view showing the configuration of the steering means. FIG. 5 is an internal perspective view showing the arrangement of the distance measuring sensor and the direction measuring means. FIG. 6 is the control block diagram. FIG. 8 is a flow chart showing the control method. FIG. 9 is an operation explanatory diagram of the mobile work robot. FIG. 10 is a conventional mobile work robot. Explanation of operation [Explanation of symbols]
11 Main body 12L Left drive wheel 12R Right drive wheel 13L Left drive motor 13R Right drive motor 14L Left rotation detector 14R Right rotation detector 15 Steering means 16 Wheel 17 Wheel shaft 18 Wheel shaft holder 20 Support shaft 21 Support Shaft fixing member 22 Angle detection means 26 Electric blower 27 Suction part 30 Direction measurement means 31 Distance sensor 32 Travel control means

Claims (6)

A drive means comprising a drive wheel for moving the main body, a drive motor for driving the drive wheel, a steering means comprising a support shaft and wheels that are free to rotate with respect to the main body, and the drive means and the steering means to control the main body A traveling control means for performing the traveling control, a direction measuring means for measuring the direction of the main body, a distance measuring means for measuring the distance from the main body to an external object, and an obstacle based on the output of the distance measuring sensor An obstacle detection means; a turning means for turning the direction of travel of the main body by 180 ° by an output of the obstacle detection means; an angle detection means for detecting a rotation angle of the support shaft; control means may be straight body target direction based on the output of the direction measuring means, to travel straight with modification based on the output angle of the angle detecting means to the target direction of the straight, and the obstacle detection hand When the obstacle detects an obstacle, the turning means turns straight after turning the direction of travel of the main body by 180 °, stops the angle detection means while the turning means is operating, and further detects the angle until it moves straight after the turning means is operated. The steering means includes a wheel, a wheel shaft that rotatably supports the wheel, a wheel shaft holding portion that supports the wheel shaft from both sides, and an inner side of the wheel shaft holding portion. A mobile work robot comprising a support shaft fixing member that urges a wheel shaft from above and from both sides, and a support shaft that connects the support shaft fixing member to an angle detection means . The mobile work robot according to claim 1, wherein the support shaft and the angle detection means are directly connected. The mobile work robot according to claim 1, wherein the support shaft fixing member is made of an elastic material. The mobile work robot according to any one of claims 1 to 3, wherein the steering means and the angle detection means are integrally removable from the main body. The mobile work robot according to any one of claims 1 to 4, wherein the wheels are arranged behind the drive wheels. The mobile work robot according to claim 5, wherein the center of gravity of the main body is located near the wheel.

Images