JP2018138118A - Visually handicapped person walking support device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve problems for example, in a prior visually handicapped person walking support device, it is difficult to grasp detailed shapes or number of obstacles which are present in a travel direction of a user, or an obstacle which does not have to be detected is detected, thereby inflicting a user.SOLUTION: A two-dimensional laser scanner is attached to a stick, and a user can set by himself/herself, a scanning surface of the two-dimensional laser scanner.SELECTED DRAWING: Figure 1

Description

The present invention relates to an apparatus for supporting a visually impaired person's independent walking using a two-dimensional laser scanner.

An object (obstacle) that cannot be detected by a white cane alone for a user who is visually impaired by sound or vibration by detecting obstacles in the direction of travel with one or more sensors using ultrasonic waves, infrared rays, electromagnetic waves, etc. Attempts have been made to inform the existence of.
For example, there is known a method of grasping the presence of an obstacle by irradiating the surroundings with ultrasonic waves or infrared rays and measuring the reflected waves, such as the technique disclosed in Japanese Patent Application Laid-Open No. 2008-099720.

JP 2008-099720 A

(Detailed obstacle problem)
However, the conventional apparatus has a problem that although it is possible to determine that there is an object near or above the foot in the traveling direction, the detailed position and shape of the object cannot be known. Furthermore, it is difficult to detect information such as a low step, not an obstacle.

(Unnecessary alarm problem)
In addition, since the range in which obstacles can be detected has a horizontal spread, it reacts to an object that is not dangerous and issues an alarm unnecessarily, which may bother the user.

The present invention has been made to solve the above problems, and obtains information on distance, height / depth, and size from an object in a direction that the user wants to know or a user at a low step. An object of the present invention is to provide a device that supports a safer walking of a visually impaired user by analyzing and informing through sound and vibration. Further, since the detection area can be finely adjusted, only necessary information can be notified.

The present invention has been made to solve the above problems.

The actuating device of the present invention comprises:
“Equipped with a cane part to be held by a visually impaired person, a two-dimensional laser scanner provided on the cane part, an obstacle detection part, a detection result notification part, and a control part,
The control unit causes the obstacle detection unit to detect an obstacle according to the two-dimensional distance data scanned by the two-dimensional laser scanner, and a detection result notification unit to notify the detection result according to the detected obstacle data. Control"
It is characterized by that.

With this feature, it is possible to selectively detect an object or step in a direction that the user wants to know, and to grasp the shape of the object or step.

As a result, the user can walk independently.

According to the present invention, the above-described obstacle detailed shape problem and unnecessary alarm problem can be solved.

The present invention will be described below with reference to the drawings.

It is a figure which shows the outline | summary of this invention apparatus. It is a figure which shows the outline | summary of this invention apparatus. It is a figure which shows the example of the alarm sound waveform of this invention apparatus. It is a figure which shows the up stairs which the two-dimensional scanner of this invention apparatus caught. It is a figure which shows the example of the alarm sound waveform of this invention apparatus. It is a figure which shows the downward staircase which the two-dimensional scanner of this invention apparatus caught. It is a figure which shows the example of the alarm sound waveform of this invention apparatus.

First, the configuration of the device of the present invention will be described with reference to FIG.
FIG. 1 shows an outline of the apparatus of the present invention.
What is drawn in a rod shape and obliquely corresponds to the cane portion in the claims. Generally, visually handicapped people use a white cane and are called “white canes”.
A grip for gripping is provided on the upper portion of the cane portion. In addition, a branch part is provided slightly above the center of the cane part, and a grip is also provided here.
In order to examine the situation of the ground while the visually handicapped person taps his or her own traveling direction with the tip of a white cane during walking, multiple grips are provided so that multiple gripping methods with less arm and wrist load can be selected. Yes.

A two-dimensional laser scanner is provided near the base of the branch. The two-dimensional laser scanner here is used to measure the linear distance by irradiating laser light, and continuously measures the distance while changing the irradiation angle of the laser light with time around a certain point on a certain plane. The point cloud data is obtained by obtaining a plurality of coordinate values derived from the angle and the distance.

In the configuration of FIG. 1, the laser beam for scanning is irradiated to the surroundings on the plane where the center axis of the cane and the center axis of the branch intersect, changing the angle depending on the time around the root of the branch. Is done. Hereinafter, this plane is referred to as a “scanning plane”.
Therefore, when the cane portion is placed vertically (along the direction of gravity), the scanning plane becomes a vertical plane and intersects the horizontal ground at a right angle.
Since the laser beam is coherent, the scanning surface becomes very thin, and as a result, has a strong directivity. Due to this characteristic, an obstacle at a position deviating on both sides from the traveling direction of the user is not erroneously detected.

From the user's point of view, the scanning plane can be set intuitively when gripping the branches. That is, since the axial direction of the central axis of the branch portion is the same (or parallel) as the scanning surface, the user can arbitrarily change the direction of the scanning surface by controlling the tip of the cane portion by gripping the branch portion. Can be set.
As described above, obstacle detection in the horizontal plane has strong directivity, so the user can detect obstacles in a wider range by rotating the pivot of the cane part while holding the branch part (pivot). Become.

FIG. 2 is a diagram showing a state where the device of the present invention is detecting obstacles (trees and bicycles) in the direction of travel of the user.
FIG. 3 is a waveform of an audio signal output from the detection result notification unit in the situation of FIG.
As described above, the two-dimensional laser scanner acquires point cloud data by continuously measuring the linear distance by changing the angle with time on a certain surface, in other words, a sectional view of the surrounding situation on the scanning surface. It is a device that is acquired as status data.
The obstacle detection unit functions to detect the presence of an obstacle by analyzing point cloud data obtained every moment.

In FIG. 2, the obstacle detection unit detects the ground surface, the bicycle, and the tree based on the point cloud data acquired by the two-dimensional laser scanner. At this time, since the angle at which the ground surface and the cane center axis intersect is known, it is taken into consideration when calculating the straight line distance on the ground surface from the tip of the cane to the obstacle.

FIG. 3 is a waveform of an audio signal notified from the detection result notification unit in the situation of FIG.
The vertical axis represents the signal amplitude, which is divided into three stages for convenience of description of FIG.
The horizontal axis is time.
The two-dimensional laser scanner measures (measures) a linear distance while rotating the laser beam clockwise in FIG. 2, and acquires point cloud data.

The obstacle detection unit analyzes the point cloud data and first detects the ground surface and a region free of obstacles (safety region).
Next, it is detected whether there is an obstacle in an area lower than the walking safety height which is a margin in the height direction necessary for the current user to walk safely. The walking safety height is derived based on the height of the user set in advance.

In the situation of FIG. 2, there is a tree in the near air, and a bicycle on a distant ground surface.
In the device according to the present invention, the two obstacles are notified to the user by an audio signal from the detection result notification unit.

The waveform of the audio signal in FIG. 3 will be described.
The first small amplitude is a low volume, low volume sound, meaning that there are no obstacles on the nearby ground surface. Since there is no need to issue an alarm for the safe area, it shall not be sensuously anxious.
The next medium amplitude means the presence of a bicycle. Since it is a clear obstacle, the amplitude should be above a certain level. Further, the frequency is increased according to the height from the ground surface at the position where the obstacle exists. As a result, the height of the position of the obstacle in the traveling direction can be grasped.

The next smaller amplitude means a blank space between the bicycle and the tree.
The next large amplitude means a tree.
Since the frequency of the tree is higher than that of the bicycle, the frequency is higher than that of the bicycle.
The amplitude is increased as the distance from the user is shorter. As a result, a voice signal having a large amplitude is obtained for a nearby obstacle, which is advantageous for the user to grasp the danger rank of the obstacle.

Further, the next small amplitude means that there is no obstacle in particular in the region above the tree and below the walking safety height.
A detection result alerting | reporting part alert | reports such an audio | voice signal continuously. The user grasps the obstacle in the traveling direction while listening to the voice signal that is continuously notified.
In the present embodiment, the sound signal waveform of FIG. 3 is set based on the concept that the visually handicapped person first checks from the foot to the head from the viewpoint of first paying attention to the foot.
On the contrary, tall visually handicapped people often hit their heads against obstacles. In this case, it may be a concept to check in order from the head to the feet.

FIG. 4 shows point cloud data when the device of the present invention shown in FIG. 1 is used before an upstairs.
The vertical axis represents the height from a certain reference plane, and the horizontal axis represents the horizontal distance from a certain reference wall.
In FIG. 4, the two-dimensional laser scanner of the device of the present invention is at a position of a height of less than 3 m and a horizontal distance of more than 5 m.
A straight line plotted with a height of just over 1.5 m and a horizontal distance of 4.5 to 6 m means a floor.
From there, it rises up to about 3m over a horizontal distance of less than 1.5m.

FIG. 5 is a waveform of an audio signal notified by the detection result notification unit in the situation of FIG.
Immediately after the start and immediately before the end of the waveform, fade-in and fade-out are performed, respectively. This is because, as described in the first embodiment, since the detection result notification unit continuously notifies the audio signal, the signal notification is suddenly started (cut-in) or suddenly stopped (cutout). ), A small noise is generated, which unpleasantly affects the user's hearing.

In the graph of FIG. 5, the frequency is constant up to the fifth horizontal axis memory. This means a floor that is a horizontal plane.
Thereafter, the frequency gradually increases. This means that the staircase steps become higher in order. In the present embodiment, the sense of distance due to the amplitude is not performed, and an example of how the ground surface is extended in the traveling direction of the user is shown.
When the staircase slope is tight, the frequency of the audio signal increases. This informs the user that there are intuitively tight stairs.
Also, the method of increasing the frequency of the audio signal is different between the staircase and the slope without a step, and changes smoothly in the case of the slope but changes stepwise in the case of the staircase. From this difference, the user can intuitively understand the shape of the gradient existing in the traveling direction.

FIG. 6 is the reverse of FIG. 4 and shows point cloud data in the case of a downward staircase.
Similarly, FIG. 7 is a waveform of an audio signal notified by the detection result notification unit in the situation of FIG. Since the stairs are descending, the frequency change gradually decreases. The effect of frequency change is the same, and the user can intuitively understand the degree and shape of the gradient.

4 and 5 illustrate audio signals that gradually increase and decrease from a specific frequency for clarity of explanation. However, in practice, a moderate frequency may be selected and gradually increased and gradually decreased. In addition, among the visually handicapped persons, those who are elderly may have a characteristic change in hearing. Therefore, the frequency may be set to a desired frequency after actually checking with an audiometer.

Up to this point, an apparatus for notifying an audio signal based on point cloud data obtained by a two-dimensional laser scanner has been described, but the notification need not be limited to an audio signal. In addition, vibration may be generated by a piezoelectric element or an actuator to excite the wand, and notification may be made by the user's tactile sense. Moreover, you may combine an audio | voice signal and a vibration.

In addition, the branch part which sets the scanning surface of a two-dimensional laser scanner does not need to be limited to the shape of the branch part of this indication. The point is that the user can easily use the cane portion as a white cane as long as the user can clearly indicate the direction of travel.

The present invention has been described with reference to preferred embodiments. However, the present invention is not limited to these embodiments, and many modifications can be made without departing from the spirit of the invention. Of course.

Using a mass-produced two-dimensional laser scanner and a cane, walking support for visually impaired people can be realized with high accuracy, and there are effects such as high practicality and welfare improvement.

None

Claims (1)

A device that supports the independent walking of the visually impaired,
A cane portion to be held by a visually impaired person,
A two-dimensional laser scanner provided on the wand,
An obstacle detection unit;
A detection result notification unit;
A control unit;
With
The two-dimensional laser scanner is provided to scan along the longitudinal direction of the wand part,
The control unit causes the obstacle detection unit to detect an obstacle according to the two-dimensional distance data scanned by the two-dimensional laser scanner, and notifies the detection result according to the detected obstacle data. Control the detection result notification unit,
This is a walking support device for visually impaired persons.