JP2009183538A - Wheelchair with autonomous traveling ability - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a wheelchair with autonomous traveling ability which allows reduction in a burden on a caregiver and allows movement which seems to others that a wheelchair user is an autonomous existence. <P>SOLUTION: The wheelchair traveling autonomously according to the operation of the caregiver is provided with a caregiver position detection means 22 which detects the position of the caregiver and the variation of the position, a caregiver face direction detection means 23 which continuously detects the face direction of the caregiver, a caregiver watching object detection means 24 which detects the watching object of the caregiver, and a travel control means 25 which controls the travel of the wheelchair on the basis of results detected by at least the caregiver face direction detection means 23 and the caregiver watching object detection means 24. The behavior of the wheelchair is not a simple copy of the movement of the caregiver, so that the movement seems to the other that the wheelchair user has selected the behavior. This allows the wheelchair user to appear to the surrounding as an independent individual. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a wheelchair used by an elderly person, a disabled person, etc., and reduces the burden on people who are engaged in care for the user, and enables an autonomous movement that impresses the independence of the user to a third party. It is a thing.

In recent years, the need for a wheelchair is increasing as the population ages. There are a wide variety of wheelchairs, and not only traditional models that are pushed by caregivers but also electric wheelchairs that users can move by operating their own joysticks. However, the operation of the electric wheelchair is not easy for many elderly people and disabled people. In addition, with the declining birthrate and aging population, there is also a tendency for human resources to care and support wheelchair users.
Under these circumstances, the development of intelligent wheelchairs that can move to some extent is required so that even small human resources can efficiently provide care and support.

Non-Patent Document 1 below discloses a robot wheelchair in which a range sensor is mounted on a wheelchair and moves autonomously following a caregiver.
This wheelchair always uses the range sensor to grasp the position of the caregiver, and when the distance to the caregiver is greater than L, the speed is reduced, and conversely, the speed is increased to decrease the speed. Accompany them.
In addition, a certain range in the vicinity of the wheelchair is set as the “insensitive area”, and when the caregiver is in the insensitive area, the follow-up to the caregiver is stopped. Therefore, the caregiver can advance from the rear of the wheelchair through the side of the wheelchair, or walk close to the side of the wheelchair and chat with the wheelchair user.
Iwase, Nakamura, Kuno “Robot Wheelchair that Moves According to Caregiver's Intent” Image Sensing Symposium Proceedings, pp.493-496, 2005

However, in the case of a wheelchair that only accompanies a caregiver, it is necessary for the caregiver to adjust the position and orientation of the wheelchair by pushing and pulling the wheelchair in various situations. The caregiver must continue to be attentive for that.
For example, when a wheelchair user appreciates a picture at a museum, the caregiver needs to push the wheelchair to a position suitable for viewing so as not to disturb other viewers and change the direction of the wheelchair toward the picture. This operation must be performed for each picture in the venue. Therefore, caregivers are forced to bear a considerable burden.

  In addition, when the wheelchair only moves according to the caregiver, there is a problem that the wheelchair user is difficult to be seen as an autonomous subject from around. The wheelchair user needs the support of the caregiver regarding the movement, but other than that, the wheelchair user is autonomous, and such a sense of autonomy is also possessed by the wheelchair user. Therefore, it is necessary to produce the behavior of the wheelchair so that it can be seen from the surroundings when moving based on the intention of the wheelchair user.

  The present invention was devised in view of such circumstances, and provides an autonomous mobile wheelchair that reduces the burden on a caregiver and allows the wheelchair user to move as seen by others as an autonomous entity. It is aimed.

The present invention is a wheelchair that moves autonomously according to a caregiver's operation, and continuously provides caregiver position detection means for detecting the position of the caregiver and a change in the position, and the face orientation of the caregiver. Based on the detection results of the caregiver face direction detection means for detecting the caregiver gaze target detection means for detecting the caregiver's gaze target, and at least the caregiver face orientation detection means or the caregiver gaze target detection means. And a movement control means for controlling movement of the wheelchair.
This wheelchair identifies the face of the caregiver and the object to be watched, and performs autonomous movement based on the identification result.

The autonomous mobile wheelchair of the present invention further includes a caregiver movement prediction unit that predicts a change in the position of the caregiver, and the movement control unit includes the prediction result of the caregiver movement prediction unit. It can also be configured to control the movement of the wheelchair.
If wheelchair movement is controlled based on the position of the caregiver's current time, the movement of the wheelchair may be delayed and the caregiver's movement may be hindered, but changes in the position of the caregiver can be predicted and utilized for wheelchair movement control. This avoids these inconveniences.

  In the autonomous mobile wheelchair according to the present invention, the caregiver position detecting means detects the stop of the caregiver, and the caregiver face direction detecting means determines that the face direction of the stopped caregiver is a predetermined direction for a predetermined time or more. When the caregiver gaze target detection means detects an exhibit as the gaze object, the movement control means moves to a position suitable for viewing the exhibit. It can be set as the structure which controls a movement.

  Further, in the autonomous mobile wheelchair according to the present invention, the movement control means controls the movement of the wheelchair so as to move to a position alongside the caregiver who appreciates the exhibit, and when the position is blocked, It is good also as a structure which controls the movement of the said wheelchair so that it may move to the movable position nearest to a person.

In the autonomous mobile wheelchair of the present invention, when the caregiver position detecting means detects the caregiver further approaching the exhibit, the movement control means determines that the distance to the exhibit is from the exhibit. It is good also as a structure which brings the said wheelchair close to the said exhibit so that it may become the same as the distance to a caregiver.
This wheelchair can be automatically moved to a position suitable for appreciating the exhibit when a caregiver points the exhibit at a museum or the like.

Moreover, in the autonomous mobile wheelchair of the present invention, when the caregiver position detecting means detects the caregiver moving, the movement control means determines that the caregiver is moved when the movement distance of the caregiver exceeds a predetermined distance. It can be set as the structure which controls the movement of the said wheelchair so that a person may be followed.
Such movement control prevents the wheelchair from following the slight movement of the caregiver who is watching. Therefore, the unstable movement of the wheelchair can be suppressed.

In the autonomous mobile wheelchair according to the present invention, the caregiver position detecting means detects the positions of the plurality of caregivers and changes in the positions, and the caregiver face direction detecting means detects the face directions of the plurality of caregivers. The caregiver gaze target detection means detects the gaze object of the caregiver closest to the wheelchair, and the movement control means controls the movement of the wheelchair so as to follow the caregiver closest to the wheelchair. can do.
When there are a plurality of caregivers, the wheelchair recognizes the caregivers as a group and follows the movement of the caregiver closest to the wheelchair.

Moreover, in the autonomous mobile wheelchair of the present invention, the caregiver position detection means detects the caregiver's stop, and the caregiver face direction detection means determines that the face direction of the stopped caregiver is the direction of the user of the wheelchair. The movement control means can control the rotation of the wheelchair so as to face the stopped caregiver when the state of facing a predetermined time or more is detected.
When the caregiver faces the wheelchair user for a predetermined time or more, the wheelchair determines that the caregiver is talking to the wheelchair user and changes the direction toward the caregiver.

Moreover, in the autonomous mobile wheelchair of the present invention, the caregiver position detection means detects a caregiver who has stopped from a plurality of caregivers, and the caregiver face direction detection means determines the face orientation of the stopped caregiver. When the state in which the direction of the wheelchair is facing for a predetermined time or more is detected, the movement control unit can control the rotation of the wheelchair so as to face the direction of the stopped caregiver.
This wheelchair recognizes a caregiver as a group when there are multiple caregivers, and if a member of the group has faced the wheelchair user for a predetermined time or more, turn to the caregiver. Change.

In the autonomous mobile wheelchair according to the present invention, the caregiver position detecting means detects the stop of the caregiver, and the caregiver face direction detecting means determines that the face direction of the stopped caregiver is a predetermined direction for a predetermined time or more. When the caretaker gaze target detection means detects another person as a caregiver's gaze object, the movement control means uses the other person, the caregiver, and the wheelchair. It can be set as the structure which controls the movement of the said wheelchair so that it may move to the position where a person can talk easily.
When the caregiver detects a state in which the caregiver is talking with another person, the wheelchair moves to a position where the wheelchair user can participate in the conversation.

  Since the autonomous mobile wheelchair according to the present invention determines and executes an action based on the face orientation of the caregiver and the gaze target, the burden on the caregiver is reduced. Moreover, since the action is not a simple copy of the caregiver's movement, it appears as an action selected by the wheelchair user to others, and the wheelchair user can be seen as an independent individual from the surroundings.

An autonomous mobile wheelchair according to an embodiment of the present invention will be described with reference to the drawings.
FIG. 1 is a block diagram showing the function of this autonomous mobile wheelchair, FIGS. 2, 17, and 20 are diagrams schematically showing the configuration and operation of this autonomous mobile wheelchair, and FIG. 4 shows the configuration of the autonomous mobile wheelchair. FIG. 16, FIG. 18, FIG. 19, FIG. 21 are flowcharts showing the operation of this autonomous mobile wheelchair, and FIG. 22 is a block diagram showing functions of the autonomous mobile wheelchair according to another embodiment. is there.

As shown in FIG. 2, the wheelchair user 40 rides on the autonomous mobile wheelchair 10, and the caregiver 50 attends the moving autonomous mobile wheelchair 10 while maintaining a certain distance 52. The autonomous mobile wheelchair 10 has a laser range sensor 15 that measures the distance from the surroundings by irradiating a laser, and a video camera 16 that projects the face direction 51 of the caregiver 50 and an object that the caregiver 50 gazes at. ing. Here, as the video camera 16, two cameras that project the face of the caregiver 50 and the direction of the line of sight of the caregiver 50 are illustrated. However, as long as the face of the caregiver 50 and the direction of the line of sight can be photographed at all times. Any camera can be used.
FIG. 3 shows the appearance of the autonomous mobile wheelchair used in the experiment. The video camera 16 is arranged with a support column at the rear of the wheelchair so that the field of view is not obstructed by the wheelchair user or the wheelchair body. Further, two laser range sensors 15 are installed, one on this column and one on the front of the wheelchair.
In this wheelchair, the video camera 16 and the laser range sensor 15 are arranged on the right side of the wheelchair on the assumption that the caregiver is attached to the right side or the rear side of the wheelchair.

As shown in FIG. 4, the autonomous mobile wheelchair 10 includes, as a drive system, a wheel motor 13 that rotates a wheel to move the wheelchair and change the direction of the wheelchair, and a motor control board 12 that controls the wheel motor 13. Equipped with a laser range sensor 15, a video camera 16, and a sensor input / output board 14 that relays input and output of signals to and from the sensor system, and controls the autonomous mobile wheelchair 10 as a control system CPU 17, a memory 11 in which a control program and various data are stored, and an image processing device 18 including a digital signal processor (DSP) that analyzes an image of the video camera 16.
In addition, the autonomous mobile wheelchair 10 also has a joystick for driving operation, a power source, and the like, but these configurations not directly related to the present invention are omitted here.

The autonomous mobile wheelchair 10 identifies the face direction of the caregiver 50 and the gaze target, and performs autonomous movement based on the identification result.
In order to perform this operation, as shown in FIG. 1, the autonomous mobile wheelchair 10 includes a surrounding environment detection unit 21 that detects a situation around the wheelchair, and a caregiver position detection unit 22 that detects the position of the caregiver 50. The caregiver face direction detecting means 23 for detecting the face direction of the caregiver 50, the caregiver gaze target detecting means 24 for detecting the object being watched by the caregiver 50, and the movement control for controlling the movement of the wheelchair. Means 25.

  The surrounding environment detection means 21 is realized by the laser range sensor 15. Here, the laser range sensor 15 uses a sensor (manufactured by Hokuyo Electric) shown in FIG. This sensor scans a semicircular field with an infrared laser (wavelength 785 nm) at a pitch of 0.36 degrees (maximum 683 steps) 240 degrees, and based on the time until the reflected light is observed. The distance to the object is detected. FIG. 6 shows the detection region 211 of one laser range sensor 15, and FIG. 7 shows the detection result of the laser range sensor 15 (a combination of the detection results of the two laser range sensors 15). Yes. In FIG. 7, the vertical axis represents the distance (unit: m) from the laser range sensor 15, and the horizontal axis represents the angle. Moreover, the surrounding environment surrounding the autonomous mobile wheelchair 10 can also be represented two-dimensionally as shown in FIG. 8 from the detection result of FIG.

  The caregiver position detection means 22 is realized by the processing of the CPU 17 that detects the position of the caregiver using the detection result of the laser range sensor 15 and the video image analysis result of the image processing device 18. As will be described later, the image processing device 18 detects the face of a person from the image of the video camera 16. When there is a person at a position where the distance detected by the laser range sensor 15 is the closest (see FIG. 7), the CPU 17 detects the person as the caregiver 50, and thereafter tracks the person as the caregiver 50.

The caregiver face direction detection means 23 is realized by the video camera 16 that captures the face of the caregiver 50 and the image processing device 18 that analyzes the video. The image processing device 18 detects a face image from the video of the video camera 16 and detects the face direction.
Several methods are known for detecting a face image. For example, as shown in the flowchart of FIG. 9, a face rectangle corresponding to a face is detected from a video camera 16 video using a discriminator using a rectangular feature (step 1). From this, a skin color area is detected (step 2), and when the face rectangle and the skin color area overlap at least partially (step 3), it can be detected as a face image (step 4).
As shown in FIG. 10, the detection of the skin color area (step 2) is based on the image of the video camera 16, and the value in the RGB color space (R, G, B each 8 bits)
R> 95, G> 40, B> 20
Max {R. G. B} -Min {R. G. B}> 15
| RG |> 15
R> G, R> B
A range of flesh-colored pixels satisfying the above condition is extracted (step 21), and the inter-frame difference of this flesh-color part is calculated to identify whether or not the sum of absolute values of inter-frame differences exceeds a threshold (step 22). ), Skin color parts with inter-frame differences less than or equal to the threshold value are excluded as skin color walls or desks are extracted (step 24), and skin color parts whose sum of absolute values of inter-frame differences exceeds the threshold value (Step 23).
FIG. 11A shows a face rectangle 711 detected from the image. As shown in FIGS. 11B, 11C, and 11D, the horizontal center line 712 of the face rectangle 711 coincides with the position of the nose. In addition, in FIGS. 11B, 11 </ b> C, and 11 </ b> D, a boundary line in the horizontal direction of the skin color region is indicated as 713.

As shown in the flowchart of FIG. 12, the face orientation is detected by using the detection results of the face rectangle detection (step 1) and the skin color area detection (step 2), and the center position of the face rectangle 711 in the horizontal direction. The difference between the (center line 712 position) and the horizontal center position of the skin color area (area between the boundary lines 713) can be calculated (step 6). The front face facing the wheelchair can be identified as a front face when the difference value obtained in step 6 is compared with a preset threshold value (step 7) and the difference value is less than the threshold value (step 7). 8). If the difference value exceeds the threshold, it can be identified that the face is not a front face (step 9).
By such processing, the image processing device 18 continuously detects the face image and the face direction from the video of the video camera 16.

The caregiver gaze target detection means 24 is realized by a video camera 16 that captures the front of the wheelchair and an image processing device 18 that analyzes the video. The image processing device 18 detects an object in the direction in which the face of the caregiver 50 faces from the video of the video camera 16.
As shown in FIG. 13, assuming that the detection position of the caregiver 50 is a vector r and the detection angle of the face is θ, the direction in which the caregiver 50 gazes is the next direction as viewed from the laser range sensor 15. .
That is, the position of the dotted line is obtained by translating the surrounding environment (solid line) detected by the laser range sensor 15 by a vector (−r), and the position on the dotted line in the θ direction is obtained from the laser range sensor 15. The direction of the position on the surrounding environment (solid line) obtained by moving the position on the dotted line by the vector r is the gaze direction of the caregiver 50 viewed from the laser range sensor 15.

  Further, the movement control means 25 is realized by the CPU 17 that performs processing in accordance with a control program stored in the memory 11. The CPU 17 rotates the wheel motor 13 through the motor control board 12 based on the detection results of the surrounding environment detection means 21, the caregiver position detection means 22, the caregiver face orientation detection means 23, and the caregiver gaze target detection means 24. An operation is instructed, and the behavior of the autonomous mobile wheelchair 10 at each time is controlled. In addition to the control program, the memory 11 includes the surrounding environment detected by the surrounding environment detection means 21, the locus data of the autonomous mobile wheelchair 10, the movement locus and face direction data of the caregiver 50, and the gaze of the caregiver 50. Data necessary for movement control such as object data is temporarily stored.

Next, the operation of the autonomous mobile wheelchair 10 will be described.
The surrounding environment detection means 21 detects the environment in the detection area 211 of the laser ranging sensor 15 as shown in FIG. Reference numeral 212 denotes a dead area in the detection area 211. When the caregiver 50 moving within the detection area 211 is detected, the autonomous mobile wheelchair 10 follows the movement of the caregiver 50 when the position of the caregiver 50 is outside the dead area 212 as shown in FIG. Then move. In this specification, not only when the wheelchair follows the caregiver 50 but also when the wheelchair goes in front of the caregiver 50 as shown in FIG.
The movement control means 25 of the autonomous mobile wheelchair 10 controls the movement of the wheelchair so as to keep a certain distance from the caregiver 50 when following the movement of the caregiver 50. That is, if the caregiver 50 moves forward, the autonomous mobile wheelchair 10 also moves forward. If the caregiver 50 turns to the right, the autonomous mobile wheelchair 10 also turns right. If the caregiver 50 moves backward, the autonomous mobile wheelchair 10 also moves backward. To do.
However, when the caregiver 50 passes through the insensitive area 212 to pass the autonomous mobile wheelchair 10 or when the caregiver 50 moves side by side with the autonomous mobile wheelchair 10 while talking to the wheelchair user 40 (at this time the caregiver 50 The movement control means 25 stops the control to keep the distance from the caregiver 50 constant.

Further, when the movement control means 25 detects an obstacle in the detection area 211 in the process of following the caregiver 50, the movement control means 25 avoids the obstacle by the following operation.
(1) When an obstacle is detected very close, the movement is stopped.
(2) Move avoiding in a direction with as few obstacles as possible.
(3) As shown in FIG. 15, when an obstacle (wall) 213 is detected in both the front detection area 2111 and the rear detection area 2112 of the autonomous mobile wheelchair 10, the obstacle 213 in the front detection area 2111 is reached. Is moved in the direction in which the distance d1 is equal to the distance d2 to the obstacle 213 in the rear detection area 2112. (Move along wall)
(4) Move following the caregiver 50's movement.
The movement control means 25 preferentially executes an action with a smaller number when avoiding an obstacle.

16 is a flow chart of the autonomous mobile wheelchair 10 when a wheelchair user 40 and a caregiver 50 appreciate an exhibit (painting) 60 together in a venue such as a museum, as shown in FIG. The operation is shown.
When the caregiver 50 stops (YES in step 31), the movement control means 25 stops the movement of the autonomous mobile wheelchair 10 (step 33) and identifies the change in the face orientation of the caregiver 50 (step 34). . When the caregiver 50 is facing the same direction for a certain time or longer (YES in step 34), the gaze object of the caregiver 50 is detected (step 37).
Further, when the caregiver 50 continues to move in step 31, the caregiver 50 is followed (step 32). Further, when re-moving is started immediately after stopping (YES in step 35), the caregiver 50 follows the caregiver 50 after moving a predetermined distance (YES in step 36) (step 32).
In addition, after the caregiver 50 moves a predetermined distance, the follow-up to the caregiver 50 is resumed in order to avoid the unstable movement of the autonomous mobile wheelchair 10 when following the trivial movement of the caregiver 50. It is. Moreover, it is the same meaning that it is a requirement that the caregiver 50 faces in the same direction for a certain time or more in Step 34.

  In step 37, when the caregiver gaze target detection means 24 detects a rectangular area surrounded by a straight line such as a frame from the direction in which the caregiver 50 faces, the movement control means 25 gazes the caregiver 50. It recognizes that the object is a painting work (step 38), and moves to a position suitable for appreciating the painting according to the procedure shown in the flowchart of FIG.

The position suitable for viewing the painting is, for example, a position adjacent to the caregiver 50 on an arc centered on the center position of the painting 60 and having a radius to the caregiver 50, as shown in FIG. This is the position facing the work at a distance of a constant multiple of the rectangular diagonal of the painting (usually about 1, generally about the length of the diagonal, and it is said that the distance from the work is suitable for viewing). Further, a position where an explainer such as a curator guides the viewer may be checked in advance, and a position not inconsistent with this may be set as a position suitable for viewing the painting.
In the procedure of FIG. 18, a position suitable for painting viewing is calculated (step 131), and it is identified whether or not there is a space in which the autonomous mobile wheelchair 10 is movable at that position (step 132). If there is a space, it moves to that position (for example, a position adjacent to the caregiver 50) (step 133). If there is another viewer at that position and there is no moving space, the robot moves to a movable position closest to that position (step 134).
When the caregiver position detection means 22 detects the caregiver 50 that is closer to the direction of the painting 60 (YES in step 135), the movement control means 25 approaches the painting 60 to the same distance as the caregiver 50. Control (step 136).
In addition, when the caregiver 50 moves toward the picture displayed next (step 137), the caregiver 50 follows the caregiver 50 (step 139) after moving the predetermined distance (step 138). Next, the process proceeds to step 31.

In step 37, when the caregiver face direction detection means 23 detects the face of the caregiver 50 who is looking at the wheelchair for a certain time or more, the movement control means 25 is used by the caregiver 50 in the wheelchair. It recognizes that the wheelchair user 40 is gazing in order to talk with the person 40 (step 39), and performs the procedure shown in the flowchart of FIG.
That is, as shown in FIG. 20, the movement control means 25 controls the rotation of the autonomous mobile wheelchair 10 so as to face the caregiver 50 (step 231). When the face of the caregiver 50 changes (YES in step 232) and the caregiver 50 resumes movement (YES in step 233), the caregiver 50 follows the caregiver 50 after moving a predetermined distance (step 234). (Step 235). Next, the process proceeds to step 31.
If the caregiver 50 who changed the face orientation in step 232 continues to look in another direction without moving (YES in step 236), the process proceeds to step 37.

In addition, when the caregiver gazing target detection means 24 detects the face of the person facing the caregiver 50 from the direction in which the caregiver 50 faces, in step 37, the movement control means 25 The caregiver 50 recognizes that the person is gazing to talk with another person (step 40), and executes the procedure shown in the flowchart of FIG.
That is, the movement control means 25 controls the position and orientation of the autonomous mobile wheelchair 10 so that the wheelchair user 40 can easily talk to both the caregiver 50 and other persons (step 331). The subsequent procedure (steps 332 to 336) is the same as the procedure of steps 232 to 236 in the flowchart of FIG.
Further, in step 37, if the caregiver's gaze target object detected by the caregiver gaze target detection means 24 is other (step 41), the movement control means 25 responds to the gaze object. The autonomous mobile wheelchair 10 is controlled to move (step 42).
For example, when a path that can travel in the direction in which the caregiver 50 is staring is detected, it can be recognized that the caregiver 50 is considering entering the path. In this case, the movement control means 25 takes the course of the autonomous mobile wheelchair 10 in the direction of the passage.

  Thus, this autonomous mobile wheelchair operates autonomously according to the face orientation of the caregiver and the gaze target that the caregiver looks at. This greatly reduces the burden on the caregiver. In addition, the behavior of this autonomous mobile wheelchair is reflected in the eyes of other people based on the intention of the wheelchair user, and the wheelchair user is recognized as an independent individual from the surroundings.

Here, although the detection result of the caregiver position detection means 22 that tracks the position of the caregiver is used for the movement control of the autonomous mobile wheelchair 10, the caregiver predicts the movement of the caregiver as shown in FIG. The movement prediction means 26 may be provided, and the caregiver's movement predicted by the caregiver movement prediction means 26 may be used for movement control of the autonomous mobile wheelchair 10.
The caregiver movement prediction means 26
(1) Predicting the caregiver's moving position at a very short time (up to about 0.5 seconds later) for a smooth movement of the wheelchair,
(2) Predicting caregiver behavior to stabilize wheelchair behavior and make it appear more autonomous,
Do either or both.

The short-term prediction of (1) is performed using prediction means such as a Kalman filter based on the caregiver position history detected by the caregiver position detection means 22. By performing movement control of the mobile wheelchair 10 using this prediction result, it is possible to stabilize the speed of movement of the wheelchair (suppress backlash).
In (2) behavior prediction, the caregiver's behavior is predicted based on the surrounding situation photographed by the video camera 16 and the gaze target detected by the caregiver gaze target detection means 24. For example, when a caregiver approaches a painting work, it is judged that “there might be a good look at this work” and the follow-up speed is slowed down. Preparing for movement to "position". If the caregiver does not stop and passes by the painting, the follow-up speed is increased and a certain distance from the caregiver is maintained. This makes it appear that the wheelchair is acting more autonomously.
When the caregiver walking on the right side of the wheelchair tries to turn left, the caregiver movement prediction means 26 predicts the left turn of the caregiver from the presence of the left turn passage, the face of the caregiver gazing at the left turn passage, and the like. Then, by controlling the speed and direction of the wheelchair based on this, the situation where the left turn of the caregiver is prevented by the wheelchair is avoided.
Also, when the caregiver tries to make a right turn, the caregiver movement predicting means 26 predicts it in the same manner as in the case of the left turn, and controls the movement of the wheelchair based on the prediction, thereby making a sudden turn of the wheelchair. Can be avoided.
The same applies when the caregiver is walking on the left side of the wheelchair and turns right or left.
In addition, when the width of the passage where the caregiver and the wheelchair are moving side by side is narrower, the caregiver movement prediction means 26 predicts the movement of the caregiver that proceeds in a row. By reducing the speed of the wheelchair based on this, it is possible to pass through a narrow spot in the form of a line led by the caregiver.

In addition, a plurality of caregivers may assist wheelchair users. At this time, the caregiver position detection means 22 of the autonomous mobile wheelchair 10 recognizes a plurality of caregivers as a group and tracks the position of each caregiver in the group.
Following the caregiver of the group follows the caregiver closest to the wheelchair. In addition, when a wheelchair user appreciates a painting with the support of a caregiver group, it can be expected that the caregiver group will welcome the wheelchair at the appropriate viewing position for the painting. Even if a moving space cannot be found at the appreciation position of the work, control is performed so that the autonomous mobile wheelchair 10 is moved to the position of the caregiver detected by the caregiver position detection means 22.
In addition, if the caregiver face direction detection means 23 of the autonomous mobile wheelchair 10 detects a caregiver who faces the autonomous mobile wheelchair 10 in the direction of the autonomous mobile wheelchair 10 for a certain time or more in the group of caregivers, The control means 25 changes the direction of the autonomous mobile wheelchair 10 toward the caregiver.

Further, the detection method of the face image and the face direction shown here is an example, and in the present invention, the face image and the face direction can be detected by other methods.
Here, the gaze target is detected from the caregiver's face direction, but the gaze direction is obtained from the caregiver's face image, and the caregiver's gaze target is detected from the gaze direction. good.
Whether or not a caregiver is talking to a wheelchair user or another person is determined not only by the direction of the face of the caregiver but also by observing the mouth movement from the caregiver's face image. good.
Alternatively, a microphone may be attached to the autonomous mobile wheelchair 10 to recognize the voice and detect the conversation state.
In addition, the video camera and laser range sensor are installed on the wheelchair on the basis that the caregiver walks to the right or rear, but the number of video cameras and laser range sensors attached to the wheelchair is increased. Or by using a sensor or camera that covers a wide field of view (angle), it is possible to appropriately control the movement of the wheelchair wherever the caregiver is located on the left or right or behind the wheelchair.

  The present invention can be widely used for wheelchairs used in various places such as hospitals, homes, exhibition facilities such as museums, movie theaters, and theaters.

The block diagram showing the function of the autonomous mobile wheelchair which concerns on embodiment of this invention The figure which shows typically the structure and tracking operation | movement of an autonomous mobile wheelchair of FIG. Diagram showing the wheelchair used in the experiment The block diagram which shows the structure of the autonomous mobile wheelchair of FIG. Diagram showing laser range sensor Diagram showing the detection area of the laser range sensor The figure which shows the detection result of the laser range sensor The figure which displayed the detection result of the laser range sensor on the two-dimensional plane Flow chart showing detection procedure of face image Flow chart showing skin color area detection procedure The figure which shows the detection result of a face image and face orientation Flow chart showing the face orientation detection procedure The figure explaining the detection method of a gaze object The figure which shows the detection area | region of the autonomous mobile wheelchair of FIG. Diagram explaining movement of autonomous mobile wheelchair along wall Flow chart showing the operation of the autonomous mobile wheelchair of FIG. The figure which shows typically the state at the time of appreciation of the picture of the autonomous mobile wheelchair of FIG. Flow chart showing the painting appreciation operation of the autonomous mobile wheelchair of FIG. The flowchart which shows the operation | movement at the time of conversation with the caregiver of the autonomous mobile wheelchair of FIG. The figure which shows typically the state at the time of conversation with the caregiver of the autonomous mobile wheelchair of FIG. The flowchart which shows the operation | movement at the time of the conversation with the caregiver and others of the autonomous mobile wheelchair of FIG. The block diagram showing the function of the autonomous mobile wheelchair which concerns on other embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Autonomous mobile wheelchair 11 Memory 12 Motor control board 13 Wheel motor 14 Sensor input / output board 15 Laser range sensor 16 Video camera 17 CPU
DESCRIPTION OF SYMBOLS 18 Image processing apparatus 21 Surrounding environment detection means 22 Caregiver position detection means 23 Caregiver face direction detection means 24 Caregiver gaze target detection means 25 Movement control means 26 Caregiver movement prediction means 40 Wheelchair user 50 Caregiver 51 Face orientation 52 Fixed distance 60 Painting 211 Laser range sensor detection area 213 Wall 711 Face rectangle 712 Face rectangle center line 713 Skin color area boundary line

Claims (10)

A wheelchair that moves autonomously according to the caregiver's movement,
Caregiver position detection means for detecting the position of the caregiver and a change in the position;
Caregiver face orientation detecting means for continuously detecting the caregiver face orientation;
Caregiver gaze target detection means for detecting the caregiver gaze object; and
Movement control means for controlling movement of the wheelchair based on at least the detection result of the caregiver face orientation detection means or caregiver gaze target detection means;
An autonomous mobile wheelchair characterized by comprising:   2. The autonomous mobile wheelchair according to claim 1, further comprising a caregiver movement prediction unit that predicts a change in the position of the caregiver, wherein the movement control unit takes into account the prediction result of the caregiver movement prediction unit. And controlling the movement of the wheelchair.   The autonomous mobile wheelchair according to claim 1 or 2, wherein the caregiver position detecting means detects the stop of the caregiver, and the caregiver face direction detecting means has a constant face orientation of the stopped caregiver. When the state in which the direction is directed for a predetermined time or more is detected, and the caregiver gaze target detecting means detects the exhibit as the gaze target, the movement control means moves to a position suitable for viewing the exhibit. An autonomous mobile wheelchair characterized by controlling the movement of the wheelchair.   The autonomous mobile wheelchair according to claim 3, wherein the movement control means controls the movement of the wheelchair so as to move to a position alongside a caregiver who appreciates the exhibit, and the position is blocked. An autonomous mobile wheelchair characterized by controlling the movement of the wheelchair so as to move to a movable position closest to the caregiver.   The autonomous mobile wheelchair according to claim 3 or 4, wherein when the caregiver position detection means detects the caregiver further approaching the exhibit, the movement control means has a distance to the exhibit. An autonomous mobile wheelchair characterized in that the wheelchair is brought close to the exhibit so as to be the same as the distance from the exhibit to the caregiver.   The autonomous mobile wheelchair according to any one of claims 3 to 5, wherein when the caregiver position detecting means detects the caregiver moving, the movement control means is configured such that the movement distance of the caregiver is a predetermined distance. An autonomous mobile wheelchair that controls the movement of the wheelchair so as to follow the caregiver when exceeding.   The autonomous mobile wheelchair according to any one of claims 3 to 6, wherein the caregiver position detecting means detects the positions of a plurality of caregivers and changes in the positions, and the caregiver face direction detecting means is the plurality of caregiver face directions detecting means. The caregiver gaze target detection means detects the gaze object of the caregiver closest to the wheelchair, and the movement control means follows the caregiver closest to the wheelchair. An autonomous mobile wheelchair characterized by controlling the movement of the wheelchair.   3. The autonomous mobile wheelchair according to claim 1 or 2, wherein the caregiver position detecting means detects a stop of a caregiver, and the caregiver face direction detecting means determines that the face direction of the stopped caregiver is the wheelchair. An autonomous mobile wheelchair characterized in that the movement control means controls the rotation of the wheelchair so as to face the direction of the stopped caregiver when a state in which the direction of the user is directed for a predetermined time or more is detected .   The autonomous mobile wheelchair according to claim 8, wherein the caregiver position detecting unit detects a stopped caregiver from among a plurality of caregivers, and the caregiver face direction detecting unit is configured to detect the stopped caregiver's The autonomy is characterized in that the movement control means controls the rotation of the wheelchair so as to face the direction of the stopped caregiver when detecting a state in which the face is facing the wheelchair for a predetermined time or more. Mobile wheelchair.   The autonomous mobile wheelchair according to claim 1 or 2, wherein the caregiver position detecting means detects the stop of the caregiver, and the caregiver face direction detecting means has a constant face orientation of the stopped caregiver. When the state in which the direction is directed for a predetermined time or more is detected, and the caregiver gaze target detecting means detects another person as a caregiver's gaze object, the movement control means is configured to detect the other person and the caregiver. An autonomous mobile wheelchair characterized by controlling the movement of the wheelchair so as to move to a position where the wheelchair user and the user of the wheelchair can easily talk to each other.