ES2441670A1 - Electronic cane for assisting with mobility of visually impaired people - Google Patents

Abstract

The present document refers to an electronic cane formed by a standard white cane of any type, the handle of which is replaced with the electronic handle to which the present invention relates. The handle contains a series of ultrasonic sensors arranged with a particular orientation which will depend on the height and size of the user and from which it is possible to discriminate two spatial regions delimited at an approximate height of the waist of the blind person. The discrimination of these regions makes it possible to locate the position of objects in front of the user, involving an appropriate warning of overhead obstacles which are impossible to detect using a conventional white cane, and in turn makes it possible to remove redundant or unnecessary information relating to elements which do not pose an actual obstacle in the user's path. In a situation in which the user may collide with a suspended object which is impossible to detect with the contact of the cane itself, a warning is produced by means of the vibration of a bracelet placed on the user's wrist. The bracelet may be connected to the electronic cane by means of an electrical connection (cable) containing a safety connector. If the cane is embedded in an obstacle (for example a drainage system grille), the connector is released, preventing the user from experiencing a dangerous pull on the wrist thereof.

Description

Electronic walking stick for mobility aid for the visually impaired.

The present invention relates to a mobility aid cane intended for the visually impaired. The equipment allows to detect the objects that remain within a certain region of the space in front of the subject and that may pose a danger to it. Detection is performed by a set of ultrasound sensors specifically oriented to discriminate different spatial regions. In the presence of an object that poses a danger to the integrity of the user and that it is not going to detect by means of the collision of the cane, a warning is issued by a vibration system placed on the user's wrist, which allows it to stop before of colliding with it.

State of the art

The White Staff is an instrument that identifies the blind and visually impaired and allows them to move autonomously, becoming an extension of their body. This tactile tool guides the blind person's steps, noting him on what type of surface he is walking and also providing information about his location. The contact of the pointer with the ground transmits vibrations to the user, which are more intense the rougher the surface on which it is located. In addition, its different management techniques facilitate the tracking and timely detection of obstacles that are in the way.

As an inconvenience, the traditional White Cane offers detection capability only below the waist, which allows walking to detect low obstacles without major problems but leaves the user exposed to suspended objects such as tree branches, fire extinguishers, vending machines, bus mirrors and trucks, etc.

At present, there are several devices that try to alleviate the limits of detection range of the traditional White Staff, using different detection paths without physical contact, generally by using different types of sensors capable of detecting objects in front of the user. In the patent documents MX20090001705, ES20090031059, ES20070001134U, ES19990001199, ES19930002250, ES19920002266, ES19900002432, ES19840282591U, CR20080010396U, US4761770, US4280204, US006671226, US6996136, US69999999, US6996996, US6996996, US6996996, US6996996, US6996996, US6999996, US6996996, US6996996, United States6996996, United States6996996 Sensing of different types, which accompanied by a subsequent processing, offer a warning of different nature to the user in the presence of objects that are in the detection region.

Despite the great technical / technological and commercial offer, the aforementioned instruments have not been widely accepted among the visually impaired group. The main drawback they present is that they have not been designed to differentiate spatial regions, so the general complaint of the users is that the device warns / alerts to any object that is in front of them, without differentiating whether the object would be detected by the traditional use of the cane or not. This circumstance generates a huge amount of information to the blind, which can cause a loss of attention to the environment.

The present invention tries to correct these defects by incorporating in the handle of the cane a set of ultrasonic sensors, which oriented as shown in Figure 6 are capable of differentiating two defined and delimited spatial regions approximately at the height of the user's waist. This implies the generation of a warning only before air obstacles impossible to detect by means of a traditional White Staff, and in turn the elimination of redundant or non-relevant information before elements that, even being in the user's path, can be detected making traditional use of the walking stick.

Detailed description of the invention

The electronic stick object of this invention is formed by an autonomous handle or handle, attachable to a single tube or a set of them (depending on whether it is removable or not) by means of an adapter element (6) allowing its compatibility with any type of tube or set of them (7), regardless of their length, brand and model.

The principle of operation of the electronic baton lies in the use of three ultrasonic sensors (3), (4) and (5) that measure the distance of nearby objects. These sensors are oriented (see Figure 6) so that two defined and delimited spatial regions are covered at the approximate height of the user's waist, as shown in Figures 3 and 4. The upper region covers from a height slightly greater than the head up to the waist of the user through the combined use of the upper sensors (3) and (4). In turn, these sensors (3) and (4) are offset at an angle to the longitudinal plane of the cane in order to adjust the width of this region to the user's shoulders. As for the lower region, it covers from the user's waist to the ground, by

the use of a lower sensor (5) whose orientation coincides with the longitudinal plane of the cane. The orientation of the ultrasonic sensors (3), (4) and (5) is determined by their mounting position, which can be through an interchangeable part (2) as shown in Figure 2, or through a housing practiced in the handle itself (1). In both cases the orientation of the sensors may vary to adjust the detection regions to the user's height.

Inside the handle (1) are the elements that control the operation of the cane: the electronics

(8)

 and the ultrasonic sensors (3), (4) and (5). Figure 9 shows a block diagram where the elements that make up the electronic part of the cane are reflected. All these elements, with the exception of the ultrasonic sensors (3), (4) and (5) and the vibrating motor (15), are integrated in the electronic circuit itself (8). The main element of this electronics (8) consists of a microcontroller (17) that manages all the elements and processes the information obtained from the ultrasonic sensors (3), (4) and (5). Electronic circuit

(8)

 integrates a battery (21) responsible for feeding both the circuit itself (8) and peripheral elements, ultrasonic sensors (3), (4) and (5) and vibrator (15). The battery is rechargeable through a specific load control circuit (20) that controls the voltage applied by an external power source on the charging connector (19). The circuit is powered by an integrated switch (18) that is accessed from outside the handle. When switching the switch (18) the microcontroller (17) is fed directly to the battery (21), thus beginning to execute the program it contains and operating the stick.

The integrated switch (18) allows you to select between three modes: Stick off; Cane in operating mode A that adapts the detection distance to a high user speed, where the environment has a low occupancy density (greater detection distance) and; Staff in mode B of operation adapting the detection distance to a low speed of the user, where the environment has a high density of occupation (lower detection distance.

The program contained in the microcontroller (17) is responsible for managing the operation of the electronic baton. This program is transferred to the microcontroller (17) through the same connector (19) used to charge the batteries (21) of the stick.

The program consists of a main routine (25) and a set of subroutines (26), (27), (28), (29) and (30) that divert the flow of the main program (25). The main program begins to run when the microcontroller (17) is fed through the main switch (18), at this time the configuration of the microcontroller peripherals (17) is loaded, which will remain unchanged during program execution. A call to the MODE function (26) is then carried out, in charge of loading the configuration that the user has selected through the mode selection switch (18). The position of the switch (18) is identified through a digital input of the microcontroller (17) and the detection distance of the sensors is loaded into the register, which can be two depending on the selected mode. Each time the selection switch (18) is actuated, there is an interruption (30) of the program that restarts the microcontroller (17) to reload the set configuration.

After this configuration, the ultrasonic sensors (3), (4) and (5) are activated through a power stage (23), excited by one of the digital outputs of the microcontroller (17). From this point an iterative loop is produced in which the sensors continuously measure the distance of the nearest objects and calculate if they are an obstacle. For this, the main routine (25) calls the TRACKING function (28) which is responsible for obtaining the distance of the nearest objects that are in the upper region (above the user's waist) covered by the sensors upper ultrasound (3) and (4).

Once the distances measured by the upper sensors (3) and (4) have been obtained, the main routine (25) makes a call to the CALCULATION function (29) responsible for calculating the position of the detected objects. To do this, first the distance values that were previously stored by the MODE function (26) are loaded and then a series of checks are carried out. In case of not fulfilling any of the established conditions, the program flow returns again to the starting point at which the TRACKING function (28) is invoked to measure again the distance of the nearest objects. On the other hand, if all the conditions established by the algorithm in which the presence of an obstacle or set of them in the upper region is determined, an exploration of the lower region is carried out. To do this, the TRACK function is invoked again

(28) that obtains the distance of the nearest object measured by the lower sensor (5). With this value the calculation algorithm continues to be executed where it is decided if the user will be able to detect the object by contact (the user's cane, his hand or his forearm will collide with the object), or on the contrary a vibratory warning will be issued to Make it stop. In particular, if the object detected in the lower region is at a distance approximately equal to the object detected in the upper area, it is assumed that the user is able to physically detect it by means of the cane, so no warning is issued. On the contrary, if the object detected in the lower region is at a distance greater than that detected in the upper zone, the activation of the vibrator (15) occurs, notifying the user of the detected object. This warning status remains active as long as the conditions established in the algorithm are met. An example can be found in figures 3 and 4. The user approaches an open window. The objects "window" and "wall" are detected, but their distances are different (the window is closer to the user than the wall, so before the cane collides with the wall, the user will have collided with the window) . In this case, the cane produces a vibration to warn the user.

The warning system consists of a wristband (10) adjustable to the wrist of the blind person that contains the vibrating motor (15). This arrangement allows a permanent contact between the vibrator (15) and the user's skin thus facilitating the perception of the warning. The vibrating motor (15) is controlled by the microcontroller (17) through one of its digital outputs through a power stage (22). The control of the vibrator (15) can be via a wired or wireless connection (radiofrequency). In the first case the electrical connection of the vibrator (16) is covered by a protector (13) that absorbs pulls made on the bracelet, thus preventing tensions in the connection cable (16) and in the vibrator itself (13). . To limit the magnitude of the pull on the wrist of the user in situations where the cane is fitted in an obstacle, a safety system (11), (12) has been provided that allows the electro-mechanical disconnection of the vibrating motor (15 ) in the event that it has a wired connection.

Brief description of the drawings

Figure 1 shows a complete view of the cane where the main elements that form it are shown, with the exception of the electronics (8) that are hidden inside the handle (1).

Figure 2 shows the elements that constitute the handle (1) where the assembly order of all the elements is represented.

Figure 3 shows a side view showing the orientation and scope of the ultrasound beam emitted / received by the sensors (3), (4) and (5).

Figure 4 shows the top view corresponding to Figure 3, where an example of an obstacle not visible by the user of the traditional White Staff can be seen.

Figure 5 shows a detail of the end of the cane where the loading and programming connector (19), the power and mode selection switch (18) and the safety connector (12) are contained.

Figure 6 shows a particular embodiment of the orientation of the ultrasonic sensors (3), (4) and (5) by a side view and a lower view of the handle.

Figure 7 shows the vibrating bracelet (10) mounted.

Figure 8 shows an internal detail of the vibrating bracelet (10) where the elements that compose it and their order of assembly are observed. This particular embodiment shows the case of a wired bracelet.

Figure 9 shows a block diagram showing the interconnection of all the elements that make up the logical part of the electronic baton.

Figure 10 shows the flow chart of the main program (25) contained in the microprocessor (17). This routine in turn contains calls to other routines that perform specific tasks.

Figure 11 shows the flowchart of the MODE subroutine (26) invoked by the main program (25) and which returns the configuration selected by the user, through the main switch (18).

Figure 12 shows the flow chart of the SLEEP function (27), which is accessed when the battery charger connection occurs.

Figure 13 shows the flow chart of the TRACKING function (28) invoked by the main program (25) and returning the distance measured by the sensors (3), (4) and (5).

Figure 14 shows the flowchart of the CALCULATION (29) function invoked by the main program (25). This function is responsible for deciding, from the measurement offered by the sensors (3), (4) and (5), if the object poses a danger and if it is necessary to activate the vibratory warning.

Figure 15 shows the flow chart of the interrupt vector (30) that is accessed when an interruption occurs due to the change of state of the main switch (18) to change the mode of operation.

Detailed description of particular embodiments

The rod for the blind object of the present invention contains an extension (7) that extends from the handle (1) to the ground, with a length that depends on the height of the user. This extension (7) can be a single element, in the case of a rigid cane or a set of segments, normally five, that are coupled together in the case of a folding cane. In both cases the material of this part / s must be of suitable characteristics that allow the user to know the type of soil through which it moves as well as the type of objects with which it interacts through the vibrations transmitted to the hit them. Among the most used materials for this element (7) are aluminum, fiberglass and carbon fiber depending on the needs of the user. The designed handle allows the use of segments of a conventional White Cane of any material and type, whether rigid or detachable, for this purpose an element (6) has been arranged at the end of the handle (1), of a resistant plastic material such as it can be Nylon, whose outer diameter adjusts to the inner diameter of the handle (1) and whose inner diameter allows housing the end of the extension (7). In the particular case of using a folding extension (7), the adjustment with the part (6) must be adequate to allow the element (7) to be disassembled with a moderate force. The connecting piece (6) can be part of the handle itself (1), not necessarily being a removable part thereof.

At the end of the cane and integral to the extension (7) is the container (24) responsible for transmitting the vibrations of the objects with which the rest of the cane interacts. This piece (24) is made of a resistant material, such as Nylon or other plastic material, and it must also be easily interchangeable because it is an element subjected to continuous friction.

The handle (1) is the main element of the cane and to which the rest of the elements that compose it are attached. The handle (1) is constructed in a light and resistant material, such as aluminum, and is hollow in most of its length in order to house the electronics (8) and the ultrasonic sensors (3) inside, (4) and (5). The handle (1) has a flat face on one of its sides that allows the user to identify the correct orientation of the cane, the location of this surface will depend on whether the user is right or left handed.

The ultrasonic sensors (3), (4) and (5) are housed in the handle itself (1) in holes made for this purpose, or by means of a removable piece (2) that, by means of its exchange, allows the orientation of the ultrasonic sensors (3), (4) and (5) without changing the handle (1). The example illustrated in Figures 1 and 2 refers to the installation of the sensors (3), (4) and (5) by means of a removable part (2), which is made of a lightweight material so that the total weight does not increase of the handle (1), as you can be ABS plastic.

The transmitter / receiver set of ultrasound (3), (4) and (5) is capable of measuring a minimum distance of 2.5 meters. The supply voltage of these elements must be compatible with the battery voltage (21), of small dimensions.

The electronic circuit is mounted on a double-sided printed plate that in turn contains a battery (21) that powers the system. This battery (21) must be small in size to be housed inside the handle (1) and must offer a nominal voltage compatible with the ultrasonic sensors (3), (4) and (5), the microcontroller (17) and the vibrating motor (15). The battery feeds the electronics through the main switch

(18) that it can be a standard switch with 1 pole and three positions and must be arranged on one side of the plate so that its state can be changed from the outside of the handle (1). The microcontroller (17) is responsible for obtaining the distance measured by the sensors (3), (4) and (5) through a serial communication. The power supply of the sensors (3), (4) and (5) is controlled by the microcontroller (17) through a power stage (23). Once the microcontroller (17) obtains the distances measured by the sensors (3), (4) and (5) a calculation is carried out according to an established algorithm that will decide if the object, or set of them, is an obstacle to The cane user. If the decision is positive, the microcontroller (17) will activate the warning vibrator (15) through one of its digital outputs through a power stage (22).

The programming of the microcontroller (17) is carried out through a connector (19) arranged on the board itself, which must have at least 5 terminals. The same programming connector (19) allows the connection of an external source to charge the battery.

In turn, there is a switch (18) that directly connected to an input of the microcontroller (17) allows the user to select between two operating modes of the stick. This switch (18) must be arranged so that it can be accessed from the outside of the cane, it can be a standard switch with 1 pole and two positions, or it can be integrated in the ignition switch itself (18) using a switch 2-pole and three positions as shown in Figure 5.

The warning system consists of a small vibrating motor (15) with the capacity to generate 0.65 G (6.38 m / s2) or more, so that it can be perceived by the user in direct contact with his wrist through its installation

shown in figure 8. The vibrator must be in contact with the user's skin in a sensitive area, such as the wrist, in order to receive the warnings. For this, the vibrator (15) is mounted on a bracelet (10) that can be made of leather, nylon fabric or any other material that is pleasant to the touch and that also has a closure system that allows its rapid placement and avoids detachments as it can be a sailboat, or a buckle system 5. The connection between the vibrating motor (15) and belt (10) is carried out by means of a piece of cloth (14) of material similar or equal to that of the belt itself (10) that sewn to the belt (10) covers and protects the vibrator (15) as shown in Figure 8. The connection between the vibrator (15) and the power stage (22) that controls it can be made through a parallel cable (16) of two wires of 1mm each one. This cable (16) can be covered by an elastic protector (13), such as a fabric edging or the like, which protects it along its entire length to prevent it from suffering from mechanical stresses. In turn, the protector (13) must be fixed to the bracelet (10), either by sewing or by means of an adhesive, so that the tension to which the protector (13) is subjected is supported by the bracelet and not by the assembly formed by the vibrator (15) and the cable (16). The parallel cable (16) and the corresponding protector (13) are divided in half of its length into two sections at whose ends there are two matching connectors, male (11) and female (12), which allow the cable to be disconnected to avoid that the user of the cane 15 suffers violent pulls in case the cane is embedded in any obstacle or moving object. These connectors

(11) and (12) must be of the air type, easy to connect / disconnect and that their polarity is not invertible due to misuse by the blind. An illustrative example can be found in Figure 7.

Claims (4)

1. Electronic walking stick for mobility aid for the visually impaired, characterized by detecting obstacles in advance and comprising:

to.

A fully autonomous handle regardless of the material and length, with adapter to be used with any single tube or set of them and that has a flat face on one of its sides that allows the user to identify the correct orientation of the cane.

b.

A set of ultrasonic sensors with modifiable orientation depending on the characteristics of the user, from which at least two spatial regions (upper and lower) can be discriminated, allowing to indicate the presence of an obstacle only when the user is not going to perceive using traditional cane.

C.

An adjustable wristband wristband wired or wirelessly communicated with the cane that incorporates a vibrating warning system

2.

 Electronic cane for mobility aid for the visually impaired according to claim 1 configurable to adapt to the specific needs of each user such as height, complexion, limb length, walking preferences.

3.

 Electronic cane for mobility aid for the visually impaired according to claims 1 and 2 that incorporates a safety system that allows electro-mechanical disconnection (if any) of the bracelet with the cane to avoid dangerous pulls or hooks for the user.

Four.

 Electronic walking stick for mobility aid for the visually impaired according to claims 1, 2, 3 and 4, which includes two or more modes of operation depending on the detection regions, the user's movement speed and / or the occupancy density of the via.