1. Field of the Invention
The present invention relates to a self-traveling vacuum cleaner having a self-traveling function and automatically cleaning a cleaning target surface.
2. Description of the Background Art
Vacuum cleaners intended to improve cleaning operability by adding a moving function have been conventionally developed. Recently, attention has been paid particularly to development of a so-called autonomous induction type self-traveling vacuum cleaner having various sensors such as a microcomputer mounted therein. The self-traveling vacuum cleaner (hereinafter, also referred to as simply “vacuum cleaner”) of this type starts making a motion by wheels driven by a drive motor when being activated. During the motion, the vacuum cleaner measures a length to an obstacle such as furniture using a plurality of sensors or the like, detects a stepped portion of a cleaning target surface, moves while avoiding the obstacle and the stepped portion, absorbs dusts adhering on the cleaning target surface using a suction port, a brush, and the like provided on a bottom of a cleaner main body, and thereby automatically cleans the cleaning target surface.
For example, Japanese Laying-Open Patent Publication Nos. 05-084200 and 2003-116758 disclose self-traveling vacuum cleaners each of which detects a stepped state on a cleaning target surface by measuring a length based on sensors, prevents falling from stairs or the like, and performs a safe cleaning operation.
Meanwhile, a conventional sensor is an infrared sensor or an ultrasonic sensor that is an active sensor. The sensor outputs an infrared ray or an ultrasonic wave from the main body, and measures a length to a target object based on a reflected ray or reflected wave of the infrared ray or the ultrasonic wave. The infrared sensor or the ultrasonic sensor is characterized in that it has directivity and can detect angles only in a present range. Namely, an obstacle detection range of one sensor is restricted to an extremely small range.
To obtain a wider obstacle detection range, therefore, it is disadvantageously necessary to increase the number of sensors, resulting in cost increase and deterioration in installation efficiency.
The present invention has been achieved to solve the conventional disadvantages. It is an object of the present invention to provide a self-traveling vacuum cleaner capable of ensuring a wider obstacle detection range by a simple constitution.
According to one aspect of the present invention, there is provided a self-traveling vacuum cleaner including: a driving unit that moves a main body relative to a desired direction; a sensor that receives a reflected light of a target object at a length within a certain length range at a predetermined angle of visibility, and that measures the length to the target object based on a phase difference of the received reflected light of the target object; and a controller that calculates the length to the target object and that controls the driving unit based on a measurement result of the sensor, wherein the sensor includes a first cell region and a second cell region for measuring a quantity of the received reflected light, the controller calculates the length to the target object based on a relative difference of a measurement result obtained in the first cell region to a measurement result obtained in the second cell region, the sensor is arranged to measure the target object in a lateral direction of a surface perpendicular to a forward direction, at the predetermined angle of visibility, an obstacle detection range having the predetermined angle of visibility of the sensor is divided into a plurality of regions along the lateral direction, the controller measures the length to the target object in each of the divided regions, and indicates the driving unit to stop the self-traveling vacuum cleaner if the length to the target object is equal to or smaller than a predetermined length in all of the divided regions of the obstacle detection range of the sensor, and the sensor includes a plurality of CCD elements arranged on a line.
According to another aspect of the present invention, there is provided a self-traveling vacuum cleaner including: a driving unit that moves a main body relative to a desired direction; a sensor that receives a reflected light of a target object at a length within a certain length range at a predetermined angle of visibility, and that measures the length to the target object based on a phase difference of the received reflected light of the target object; and a controller that calculates the length to the target object and that controls the driving unit based on a measurement result of the sensor.
Preferably, the sensor includes a first cell region and a second cell region for measuring a quantity of the received reflected light, and the controller calculates the length to the target object based on a relative difference of a measurement result obtained in the first cell region to a measurement result obtained in the second cell region.
Preferably, the sensor is arranged to measure the target object in a lateral direction of a surface perpendicular to a forward direction, at the predetermined angle of visibility, an obstacle detection range having the predetermined angle of visibility of the sensor is divided into a plurality of regions along the lateral direction, and the controller measures the length to the target object in each of the plurality of regions, and indicates the driving unit to stop the self-traveling vacuum cleaner if the length to the target object is equal to or smaller than a predetermined length in all of the plurality of regions of the obstacle detection range of the sensor.
Preferably, the sensor is arranged to measure the target object in a lateral direction of a surface perpendicular to a forward direction, at the predetermined angle of visibility, an obstacle detection range having the predetermined angle of visibility of the sensor is divided into a plurality of regions along the lateral direction, and the controller measures the length to the target object in each of the plurality of regions, indicates, if the length to the target object is equal to or smaller than a predetermined length in the plurality of regions on both ends of the obstacle detection range of the sensor, respectively, the driving unit to stop the self-traveling vacuum cleaner, and indicates, if the length to the target object is equal to or smaller than the predetermined length in at least one of the regions on the both ends of the obstacle detection range, the driving unit to start an avoidance motion of avoiding toward the other region out of the regions on the both ends of the obstacle detection range.
Preferably, the sensor includes a plurality of CCD elements arranged on a line.
Preferably, the sensor is arranged to measure the target object in a lateral direction of a surface perpendicular to a forward direction, at the predetermined angle of visibility, an obstacle detection range having the predetermined angle of visibility of the sensor is divided into a first region in a direction of a forward region of the main body and a second region outward of the forward region of the main body, and the controller measures the length to the target object in the second region, and indicates the driving unit to stop the self-traveling vacuum cleaner if the length to the target object in the second region is changed in a predetermined period.
Preferably, the controller measures the length to the target object in the first region, and indicates the driving unit to stop the self-traveling vacuum cleaner if the length to the target object in the first region is equal to or smaller than a predetermined length.
Preferably, the sensor is arranged to measure a length to a cleaning target surface in a region in a forward direction, and the controller measures the length to the cleaning target surface in the region in the forward direction, and indicates the driving unit to stop the self-traveling vacuum cleaner if the length to the cleaning target surface is changed from the certain length.
In particular, the controller determines that a stepped portion is present if the length to the target object is larger than the certain length.
In particular, the controller determines that an obstacle is present if the length to the target object is smaller than the certain length.
Preferably, the sensor is arranged to measure a cleaning target surface in a direction of a forward region of the main body and the target object outward of the forward region of the main body, at the predetermined angle of visibility, an obstacle detection range having the predetermined angle of visibility of the sensor is divided into a first region inward of the forward region of the main body and a second region outward of the forward region of the main body, and the controller measures the length to the target object in the second region, and indicates the driving unit to stop the self-traveling vacuum cleaner if the length to the target object in the second region is changed in a predetermined period and is smaller than the certain length.
In particular, the controller measures a length to the cleaning target surface in the first region, and indicates the driving unit to stop the self-traveling vacuum cleaner if the length to the cleaning target surface in the first region is changed.
In particular, the sensor is provided on one end of the main body in a lateral direction of the main body, has a predetermined depression angle with respect to a horizontal level in the forward direction, and is arranged laterally to be shifted by a predetermined angle from the horizontal level in the forward direction so as to face the other end of the main body in the forward direction.
Preferably, the sensor is arranged to measure the target object in a direction of height of a surface perpendicular to a forward direction, at the predetermined angle of visibility, an obstacle detection range having the predetermined angle of visibility of the sensor is divided into a first region for detecting an upper region than a maximum height of the main body in the direction of height and a second region for detecting a lower region than the maximum height of the main body in the direction of height, and the controller measures the length to the target object in each of the first region and the second region, indicates the driving unit to stop the self-traveling vacuum cleaner if the length to the target object in the first region of the obstacle detection range of the sensor is equal to or smaller than a predetermined length and the length to the target object in the second region is equal to or smaller than the predetermined length, and fails to indicate the driving unit to stop the self-traveling vacuum cleaner if the length to the target object in the first region is equal to or smaller than the predetermined length and the length to the target object in the second region is not equal to or smaller than the predetermined length.
Preferably, the sensor is arranged aslant so as to measure the target object in each of a direction of height and a lateral direction of a surface perpendicular to a forward direction, at the predetermined angle of visibility, an obstacle detection range having the predetermined angle of visibility of the sensor is divided into a first region for detecting an upper region than a maximum height of the main body in the direction of height and a second region for detecting a lower region than the maximum height of the main body in the direction of height, and the controller measures the length to the target object in each of the first region and the second region, indicates the driving unit to stop the self-traveling vacuum cleaner if the length to the target object in the first region of the obstacle detection range of the sensor is equal to or smaller than the predetermined length and the length to the target object in the second region is equal to or smaller than the predetermined length, and fails to indicate the driving unit to stop the self-traveling vacuum cleaner if the length to the target object in the first region is equal to or smaller than the predetermined length and the length to the target object in the second region is not equal to or smaller than the predetermined length.
Preferably, the sensor is arranged to measure a cleaning target surface in a region in a forward direction of the main body and the target object in the forward direction, at the predetermined angle of visibility, an obstacle detection range having the predetermined angle of visibility of the sensor is divided into a first region in the forward direction of the main body and a second region in a direction of the cleaning target surface in the region of the main body in the forward direction, and the controller measures a length to the cleaning target surface in the second region, indicates the driving unit to stop the self-traveling vacuum cleaner if the length to the cleaning target surface in the second region is changed.
In particular, the controller measures the length to the target object in the forward direction in the first region, and indicates the driving unit to stop the self-traveling vacuum cleaner if the length to the cleaning target surface in the first region is equal to a smaller than a predetermined length.
The sensor of the self-traveling vacuum cleaner of the present application includes a sensor for measuring a length to a target object at a predetermined angle of visibility, and a controller that controls a driving unit based on a measurement result of the sensor. Namely, an obstacle or the like can be detected in a wide range using the single sensor having the predetermined angle of visibility, cost can be reduced, and installation efficiency can be improved.
The foregoing and other objects, features, aspects and advantages of the present invention will become more apparent from the following detailed description of the present invention when taken in conjunction with the accompanying drawings.
Embodiments of the present invention will be described hereinafter in detail with reference to the drawings. In the drawings, same or corresponding constituent elements are denoted by the same reference symbols and will not be repeatedly described.
Referring to
Passive sensor 3 receives a reflected light of an external light of the target object at a length within a certain length range at a predetermined angle of visibility, and measures a length to the target object based on a phase difference of the received reflected light of the target object. In the first embodiment, passive sensor 3 is a line sensor including a plurality of CCD elements (cells) which are provided linearly.
Referring to
Sensor unit 8 outputs the detection result acquired by sensor 3 to controller 2 in response to a command from controller 2. Position/speed detector 3# detects the position of the vacuum cleaner and the speed of the vacuum cleaner that performs a forward operation in response to a command from controller 2, and outputs the detected position and speed to controller 2. Driving controller 9 controls the rotation speed and forward direction of motor 4#, i.e., the direction of wheels 2a and 2b or the like in response to a command from controller 2.
Referring to
A length measurement method by detecting a phase difference based on sensor 3 according to this embodiment will first be described.
Referring to
Specifically, a length E to a subject P is represented by the following equation according to triangulation.
E=D×F/ΔX
Herein, D denotes a base length and F denotes a focal length of the lens.
By measuring phase difference ΔX, length E to subject P can be calculated.
Referring to
As shown in
Referring to
As shown in
As shown in
Specifically, if the shift amount of the elements in sense region RA is 0, the correlation value is 250. If the shift amount is 1, the correlation value is 150. If the shift amount is 2, the correlation value is 0. If the shift amount is 3, the correlation value is 150. If the shift amount is 4, the correlation value is 300.
Referring to
As shown in
Based on the above-described method, sensor 3 calculates length E to each of a plurality of preset points in the obstacle detection range. If obtained length E is shorter than a predetermined threshold, it is determined that sensor 3 react and that a target object can be detected.
The vacuum cleaner according to this embodiment of the present invention can ensure the wide obstacle detection range using a single passive sensor. While a plurality of active sensors need to be provided so as to ensure the same wide obstacle detection range, it suffices to use a single passive sensor according to the first embodiment of the present invention. Therefore, cost can be reduced and installation efficiency can be improved, as compared with the conventional techniques.
Obstacle detection executed by controller 2 according to the first embodiment of the present invention will now be described.
Referring to
Referring to
As shown in
If sensor 3 reacts, the processing proceeds to step S2, in which controller 2 determines whether sensor 3 reacts in all sensor blocks SP1 to SP6 of obstacle detection range 5. If sensor 3 reacts in all sensor blocks SP1 to SP6 of obstacle detection range 5, sensor 3 recognizes that an obstacle such as a wall difficult to avoid is present (step S3). Controller 2 indicates driving controller 9 to control the vacuum cleaner to stop moving forward (step S4).
If controller 2 determines in step S2 that sensor 3 does not react in all sensor blocks SP1 to SP6 of obstacle detection range 5, the processing proceeds to step S5. In step S5, controller 2 determines whether sensor 3 reacts in both of sensor blocks SP1 and SP6 on both ends of obstacle detection range 5 (step S5).
If controller 2 determines in step S5 that sensor 3 reacts in both of sensor blocks SP1 and SP6 on both ends of obstacle detection range 5, the processing proceeds to step S3 in which controller 2 recognizes that the obstacle such as the wall difficult to avoid is present, and indicates driving controller 9 to control the vacuum cleaner to stop moving forward as described above (step S4).
On the other hand, if controller 2 determines that sensor 3 does not react in either of sensor blocks SP1 and SP6 on both ends of obstacle detection range 5, controller 2 recognizes the obstacle is avoidable in a non-reaction direction of sensor blocks SP1 and SP6 on both ends of obstacle detection range 5 (step S6). Controller 2 then indicates driving controller 9 to control the vacuum cleaner to start an avoidance motion in the non-reaction direction (step S7). The avoidance motion is a motion of the vacuum cleaner according to a program stored in a storage unit which is not shown. For example, the program can be set so that the vacuum cleaner moves in entire obstacle detection range 5 until sensor 3 reacts.
As shown in
As shown in
With the obstacle detection according to the first embodiment of the present invention, single passive sensor 3 can determine a shape of the obstacle, i.e., determine whether the obstacle is an obstacle such as a wall difficult to avoid or an avoidable obstacle.
In the first embodiment of the present invention, the obstacle detection method for detecting the obstacle or the like in front of the vacuum cleaner in the forward direction thereof using sensor 3 has been described. In a modification of the first embodiment, an obstacle detection method capable of detecting a wall or the like in a side surface direction will be described.
Referring to
Referring to
As shown in
In the modification of the first embodiment of the present invention, an obstacle in front of the vacuum cleaner in the forward direction thereof is detected using sensor block 5a, and an obstacle outward of the main body width of the vacuum cleaner in the side surface direction thereof is detected using sensor block 5b.
Referring to
Similarly to the first embodiment, the vacuum cleaner is activated and starts a cleaner operation (step S30). Controller 2 determines whether sensor 3 reacts in sensor block 5b of obstacle detection range 5 (step S31). If sensor 3 does not react in sensor block 5b, controller 2 continues to execute step S31. If sensor 3 reacts in sensor block 5b, controller 2 determines whether a length to a target object to which sensor 3 reacts is changed in a predetermined period (step S32).
If controller 2 determines in step S32 that the length to the target object to which sensor 3 reacts is not changed in the predetermined period, controller 2 recognizes that the vacuum cleaner makes a translatory motion relative to a wall (step S33). The vacuum cleaner continues to move forward (step S34). Namely, controller 2 does not indicate driving controller 9 to control the vacuum cleaner to stop moving forward. The processing returns to first step S31.
If controller 2 determines in step S32 that the length to the target object to which sensor 3 reacts is changed in the predetermined period, controller 2 determines whether the length to the target object to which sensor 3 reacts is smaller (step S35).
If controller 2 determines in step S35 that the length to the target object to which sensor 3 reacts is shorter, controller 2 recognizes that the vacuum cleaner is closer to a wall (step S36). Controller 2 then indicates driving controller 9 to control the vacuum cleaner to stop moving forward (step S37).
If controller 2 determines in step S35 that the length to the target object to which sensor 3 reacts is not shorter, that is, the length is longer, controller 2 recognizes that the vacuum cleaner is farther from the wall (step S38). The processing then proceeds to step S34.
Referring to
In this case, in step S31 in the flowchart of
Referring to
In this case, the processing proceeds to steps S31 and S32 in the flowchart of
Referring to
In this case, the processing proceeds to steps S31 and S32 in the flowchart of
As can be seen, with the obstacle detection according to the modification of the first embodiment of the present invention, it is possible to determine whether the vacuum cleaner makes a translatory motion relative to the wall, whether the vacuum cleaner is closer to the wall, or whether the vacuum cleaner is farther from the wall using sensor block 5b of obstacle detection range 5.
Further, it is possible to detect the obstacle in the forward direction of the vacuum cleaner using sensor block 5b of obstacle detection range. According to the conventional techniques, it is disadvantageously necessary to arrange sensors for the obstacle in the forward direction and that in the side surface direction of the vacuum cleaner, respectively, to detect these obstacles. With the configuration of the vacuum cleaner according to the modification of the first embodiment of the present invention, by contrast, the obstacles can be detected using the single passive sensor. Therefore, cost can be reduced and installation efficiency can be improved.
In the first embodiment, the instances of detecting the obstacle in the forward direction and the obstacle such as the wall relative to which the vacuum cleaner makes a translatory motion have been described. In a second embodiment of the present invention, obstacle detection capable of detecting a stepped portion and an obstacle in the forward direction will be described.
Referring to
Referring to
As shown in
If controller 2 determines that the length to the target object to which sensor 3 reacts is changed, the processing proceeds to step S12 in which controller 2 determines whether the length to the target object to which sensor 3 reacts is longer (step S12). If controller 2 determines in step S12 that the length to the target object to which sensor 3 reacts is longer, controller 2 recognize that a stepped portion is present (step S13). Controller 2 then indicates driving controller 9 to control the vacuum cleaner to stop moving forward (step S14).
If controller 2 determines in step S12 that the length to the target object to which sensor 3 reacts is not longer, that is, the length is shorter, controller 2 recognize that an obstacle is present (step S15). Controller 2 then indicates driving controller 9 to control the vacuum cleaner to stop moving forward (step S16).
In the example of
In the example of
As can be seen, with the obstacle detection according to the second embodiment of the present invention, the stepped portion and the obstacle in the forward direction can be detected. The obstacle detection according to the second embodiment of the present invention particularly enables obstacle detection in a wide range since the passive sensor having the predetermined angle of visibility is used.
In the second embodiment, the obstacle detection for detecting the stepped portion and the like on the cleaning target surface has been described. In a third embodiment of the present invention, obstacle detection for detecting an obstacle above the main body of the vacuum cleaner will be described.
Referring to
Referring to
Referring to
As shown in
If controller 2 determines in step S22 that sensor 3 does not react in sensor block 5d of obstacle detection range 5, controller 2 recognizes that the obstacle which does not obstruct the passage of the vacuum cleaner is present (step S25). Controller 2 then indicates driving controller 9 to control the vacuum cleaner to continue to move forward (step S26).
Referring to
In the example of
Referring to
In this example, since sensor 2 reacts in sensor block 5 in step S21 in the flowchart of
The example of detecting the obstacle in the upper region than main body 1 has been described. An obstacle in the forward direction can be also detected using sensor block 5d of obstacle detection range 5.
As can be seen, with the obstacle detection of the self-traveling vacuum cleaner according to the third embodiment of the present invention, the obstacle in the upper region than the maximum height of main body 1 can be detected, and it can be determined whether the vacuum cleaner can pass or cannot pass. An efficient cleaning operation can be, therefore, performed.
Referring to
Referring to
As shown in
Accordingly, when the obstacle detection according to the flowchart of
Referring to
Referring to
As shown in
By applying the obstacle detection method according to the flowchart of
By applying the obstacle detection method according to the flowchart of
According to the conventional techniques, it is disadvantageously necessary to arrange sensors for the obstacle in the forward direction and that in a direction of the cleaning target surface, respectively, to detect these obstacles. With the configuration of the vacuum cleaner according to the modification of the third embodiment of the present invention, by contrast, the obstacles can be detected using the single passive sensor. Therefore, cost can be reduced and installation efficiency can be improved.
In the modification of the first embodiment of the present invention, the obstacle detection for detecting the target object such as the wall in the forward direction and that relative to which the vacuum cleaner makes a translatory motion, in the side surface direction has been described. In a fourth embodiment of the present invention, an example of detecting a stepped portion in the forward direction and a wall or the like relative to which the vacuum cleaner makes a translatory motion in the side surface direction will be described.
Referring to
Referring to
As shown in
According to the conventional techniques, it is disadvantageously necessary to arrange sensors for the obstacle such as the stepped portion in the direction of the cleaning target surface and the obstacle such as the wall relative to which the vacuum cleaner makes a translatory motion in the side surface direction, respectively, to detect these obstacles. With the configuration of the vacuum cleaner according to the fourth embodiment of the present invention, by contrast, the obstacles can be detected using the single passive sensor. Therefore, cost can be reduced and installation efficiency can be improved.
Moreover, according to the fourth embodiment of the present invention, sensor 3a is provided on one end of the front surface of main body 1, has the predetermined depression angle with respect to the horizontal level in the forward direction, and is arranged to face the other end of the front surface. While a sense reaction of a sensor generally tends to be deteriorated at a close range, the configuration of the vacuum cleaner in this embodiment can secure a sufficient length from sensor 3a to obstacle detection range 4 and enables sufficiently highly accurate detection.
Although the present invention has been described and illustrated in detail, it is clearly understood that the same is by way of illustration and example only and is not to be taken by way of limitation, the spirit and scope of the present invention being limited only by the terms of the appended claims.
Number | Date | Country | Kind |
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JP2004-024277 | Jan 2004 | JP | national |