CN114177017A - Blind person trip auxiliary system - Google Patents

Abstract

The utility model provides a blind person auxiliary system that goes out, relates to supplementary disabled person technical field that goes out for solve current blind person's trip appurtenance function singleness, with high costs, the not good problem of interactivity. The technical points of the invention comprise: the system comprises a cane end and a moving end, wherein the cane end comprises a data acquisition module, a main control module, an alarm module and a key instruction acquisition module; the data acquisition module comprises an obstacle distance data acquisition submodule and a blind stick posture acquisition submodule; the main control module comprises an obstacle avoidance reminding sub-module and a blind stick falling detection sub-module; the mobile terminal comprises a voice navigation module and a falling location help-seeking module; the falling location help-seeking module comprises a falling state judgment submodule, a GPS (global positioning system) positioning submodule and a help-seeking information sending module. The invention combines the functions of positioning navigation, obstacle avoidance, voice interaction and the like, has the characteristics of high portability, low cost, easy operation, humanization and the like, and provides powerful guarantee for safe and convenient travel of the blind and the visually impaired people in a real sense.

Description

Blind person trip auxiliary system

Technical Field

The invention relates to the technical field of assisting disabled people in going out, in particular to a blind person going out assisting system.

Background

The existing travel assisting tool for the blind is single in function, can meet certain blind guiding requirements of the blind, but cannot effectively provide guarantee for the blind to travel alone safely, and further cannot provide comprehensive and comprehensive services for the blind and visually-impaired people to travel. Through analysis of the existing blind guiding products, the intelligent blind guiding stick only provides some simple obstacle avoidance functions and cannot perform route planning and navigation functions; although the blind guiding robot has perfect functions, the blind guiding robot generally has the defects of high price, portability and the like; the pair of glasses for the blind is convenient to carry, but has the problems of high price or single function, and can not serve blind people. Therefore, how to manufacture a set of blind person trip assisting system which is low in cost, high in efficiency, good in interactivity, safe and portable is a problem to be solved urgently.

Disclosure of Invention

In view of the above problems, the invention provides a travel assisting system for the blind, which is used for solving the problems of single function, high cost and poor interactivity of the existing travel assisting tool for the blind.

A blind person trip assisting system comprises a blind stick end and a moving end, wherein the blind stick end and the moving end are communicated in a wireless mode; wherein the content of the first and second substances,

the blind stick end comprises a data acquisition module, a main control module, an alarm module and a key instruction acquisition module;

the data acquisition module comprises an obstacle distance data acquisition submodule and a blind stick posture data acquisition submodule; the obstacle distance data acquisition submodule is used for detecting distance data between an obstacle and the blind stick and sending the distance data to the main control module; the blind stick attitude data acquisition submodule is used for acquiring attitude data of a blind stick in real time and sending the attitude data to the main control module;

the main control module comprises an obstacle avoidance reminding sub-module and a blind stick falling detection sub-module; the obstacle avoidance reminding submodule is used for comparing the distance data with different distance thresholds and sending different obstacle avoidance alarm information to the alarm module; the tactile stick falling detection submodule is used for fusing and solving the attitude data to obtain a three-axis Euler angle, and sending a falling signal to the mobile terminal when the Euler angle changes;

the alarm module carries out early warning in different forms according to different obstacle avoidance alarm information;

the key instruction acquisition module is used for acquiring a cane end key instruction and sending the key instruction to the mobile end; the key instruction comprises a voice navigation instruction;

the mobile terminal comprises a voice navigation module and a falling location help-seeking module;

the voice navigation module is used for calling a network map service to perform voice navigation after receiving a voice navigation instruction sent by the tactile stick end;

the falling location help-seeking module comprises a falling state judgment submodule, a GPS (global positioning system) positioning submodule and a help-seeking information sending module; the falling-down state judgment submodule is used for judging whether the blind person is in a falling-down state according to a falling-down signal sent by the blind stick end, and calling the GPS positioning submodule to acquire the current position of the blind person under the condition of judging that the blind person is in the falling-down state; the distress message sending module is used for sending the position of the blind and distress messages to the designated contact person.

Furthermore, the obstacle distance data acquisition submodule is an ultrasonic sensor, and the distance threshold value is divided into a first-level safety distance, a second-level safety distance and a third-level safety distance.

Further, when the distance data in the obstacle avoidance reminding submodule is smaller than or equal to the first-level safety distance, obstacle avoidance alarm information is used for sending a mild alarm; when the distance data is smaller than or equal to the secondary safety distance, the obstacle avoidance alarm information is used for sending interval long alarm; and when the distance data is less than or equal to the three-level safety distance, sending out short-interval and urgent alarm by the obstacle avoidance alarm signal.

Further, the first-level safety distance, the second-level safety distance and the third-level safety distance in the distance threshold are respectively 70CM, 50CM and 25 CM.

Further, the alarm module is an active buzzer; the blind stick attitude data acquisition submodule is a six-axis attitude sensor MPU 6050.

Further, the wireless mode is bluetooth.

Furthermore, the key-press instruction sent by the cane end also comprises a weather forecast playing instruction; the mobile terminal also comprises a weather forecast playing module, and the weather forecast playing module is used for calling a network map and a weather forecast service function to play the weather forecast after receiving a weather forecast playing instruction sent by the cane terminal.

Furthermore, the obstacle distance data acquisition submodule is a monocular camera module, and the monocular camera module detects the distance between the obstacle and the cane by using the acquired image data.

Further, the specific process of the monocular camera module for detecting the distance between the obstacle and the cane by using the acquired image data is as follows: acquiring an obstacle imaging picture through a monocular camera, wherein the monocular camera is arranged at a fixed position of the tactile stick, and an optical axis of the monocular camera is parallel to the ground; acquiring the height H and the image distance f between the monocular camera and the ground level, and acquiring the coordinates (x, y) of the obstacle according to a first coordinate system with the center of the obstacle imaging picture as an origin; calculating the horizontal distance d between the obstacle and the monocular camera according to the following formula:

compensating the horizontal distance according to an image distance error formula and/or an incident error formula of the monocular camera to obtain an actual distance; and parameters and the installation position of the monocular camera are fixed.

Furthermore, the blind stick end adopts arduino main control chip to realize each module function of the blind stick end.

The beneficial technical effects of the invention are as follows:

the invention considers the combination of functions of positioning, navigation, obstacle avoidance, voice interaction and the like, improves some methods, designs a set of blind person trip auxiliary system which has the functions of positioning, navigation, route planning, voice interaction, obstacle avoidance and the like and has the characteristics of high portability, low cost, easy operation, humanization and the like based on the mobile intelligent terminal equipment, and provides powerful guarantee for safe and convenient trip of blind persons and visually impaired persons in a real sense.

Drawings

The invention may be better understood by referring to the following description in conjunction with the accompanying drawings, in which like reference numerals are used throughout the figures to indicate like or similar parts. The accompanying drawings, which are incorporated in and form a part of this specification, illustrate preferred embodiments of the present invention and, together with the detailed description, serve to further explain the principles and advantages of the invention.

Fig. 1 is a block diagram of a structure of a travel assisting system for the blind;

fig. 2 is a block diagram of a layered structure of a blind person travel assistance system according to an embodiment of the present invention;

FIG. 3 is a driving circuit for the sounding function of the tactile stick in the embodiment of the assistant system for the blind person going out;

fig. 4 is a schematic flow chart of a positioning function program in an embodiment of the travel assisting system for the blind;

fig. 5 is a flow chart of a help-seeking short message function in a specific embodiment of the blind travel assisting system of the invention.

Detailed Description

In order that those skilled in the art will better understand the disclosure, exemplary embodiments or examples of the disclosure are described below with reference to the accompanying drawings. It is obvious that the described embodiments or examples are only some, but not all embodiments or examples of the invention. All other embodiments or examples obtained by a person of ordinary skill in the art based on the embodiments or examples of the present invention without any creative effort shall fall within the protection scope of the present invention.

The embodiment of the invention provides a travel assisting system for blind people, as shown in fig. 1, the system comprises a cane end 1 and a moving end 2, wherein the cane end 1 and the moving end 2 communicate in a wireless mode; wherein the content of the first and second substances,

the cane end 1 comprises a data acquisition module 11, a main control module 12, an alarm module 13 and a key instruction acquisition module 14;

the data acquisition module 11 comprises an obstacle distance data acquisition submodule 111 and a blind stick posture data acquisition submodule 112; the obstacle distance data acquisition submodule 111 is used for detecting distance data between an obstacle and the blind stick and sending the distance data to the main control module 12; the tactile stick posture data acquisition submodule 112 is used for acquiring the posture data of the tactile stick in real time and sending the posture data to the main control module 12;

the main control module 12 includes an obstacle avoidance reminding sub-module 121 and a blind stick falling detection sub-module 122; the obstacle avoidance reminding submodule 121 is configured to compare the distance data with different distance thresholds, and send different obstacle avoidance alarm information to the alarm module; the tactile stick drop detection submodule 122 is configured to fuse and solve the attitude data to obtain a three-axis euler angle, and send a drop signal to the mobile terminal 2 when the euler angle changes;

the alarm module 13 performs different forms of early warning according to different obstacle avoidance alarm information;

the key instruction acquisition module 14 is used for acquiring a key instruction of the cane end 1 and sending the key instruction to the mobile end 2; the key instruction comprises a voice navigation instruction;

the mobile terminal 2 comprises a voice navigation module 21 and a falling location help-seeking module 22;

the voice navigation module 21 is configured to call a network map service to perform voice navigation after receiving a voice navigation instruction sent by the tactile stick terminal 1;

the falling location distress module 22 comprises a falling state judgment submodule 221, a GPS positioning submodule 222 and a distress information sending module 223; the falling state judgment submodule 221 is used for judging whether the blind person is in a falling state according to a falling signal sent by the blind stick end, and calling the GPS positioning submodule 222 to acquire the current position of the blind person under the condition of judging that the blind person is in the falling state; the distress message sending module 223 is used for sending the position of the blind and the distress message to the designated contact.

In this embodiment, optionally, the obstacle distance data acquisition submodule 111 is an ultrasonic sensor, and the distance threshold is divided into a first-level safety distance, a second-level safety distance, and a third-level safety distance.

In this embodiment, optionally, when the distance in the obstacle avoidance reminding sub-module 121 is less than or equal to the first-level safety distance, the obstacle avoidance warning signal is to send a gentle warning; when the distance is less than or equal to the secondary safety distance, the obstacle avoidance alarm signal sends out an interval length alarm; when the distance is smaller than or equal to the third-level safety distance, the obstacle avoidance alarm signal sends out an alarm with short interval and rush.

In this embodiment, optionally, the first-level safety distance, the second-level safety distance, and the third-level safety distance in the distance threshold are 70CM, 50CM, and 25 CM.

In this embodiment, optionally, the alarm module 13 is an active buzzer; the blind stick attitude data acquisition submodule 112 is a six-axis attitude sensor MPU 6050.

In this embodiment, optionally, the wireless mode is bluetooth.

In this embodiment, optionally, the key instruction sent by the cane end 1 further includes a weather forecast playing instruction; the mobile terminal 2 further includes a weather forecast playing module 23, and the weather forecast playing module 23 is configured to call a network map and a weather forecast service function to play a weather forecast after receiving a weather forecast playing instruction sent by the cane terminal 1.

In this embodiment, optionally, the obstacle distance data acquisition submodule 111 is a monocular camera module, and the monocular camera module detects a distance between the obstacle and the cane by using the acquired image data.

In this embodiment, optionally, the specific process of the monocular camera module detecting the distance between the obstacle and the cane by using the acquired image data is as follows: acquiring an imaging picture of the obstacle through a monocular camera, wherein the monocular camera is arranged at a fixed position of the tactile stick, and an optical axis of the monocular camera is parallel to the ground; acquiring the height H and the image distance f between a monocular camera and a ground plane, and acquiring coordinates (x, y) of an obstacle according to a first coordinate system with the center of an obstacle imaging picture as an origin; calculating the horizontal distance d between the obstacle and the monocular camera according to the following formula:

compensating the horizontal distance according to an image distance error formula and/or an incidence error formula of the monocular camera to obtain an actual distance; and parameters and the installation position of the monocular camera are fixed.

In this embodiment, optionally, the blind stick end 1 adopts an arduino main control chip to realize functions of each module of the blind stick end 1.

Another embodiment of the invention provides a travel assisting system for the blind, which adopts a layered design idea and is divided into three layers, namely a hardware layer, a transmission layer and an application layer. The structure is shown in fig. 2. The hardware layer of the blind person trip auxiliary system has the main functions of intelligent obstacle avoidance, falling detection and key starting. And in data communication, the interconnection between the tactile stick and the mobile phone is realized by using a Bluetooth technology. The software layer integrates the functions of voice navigation, GPS positioning help seeking, falling alarm help seeking, trip weather forecast and voice communication. The following describes embodiments of the present invention in detail.

1. Hardware design

A. Master control chip

The arduino is adopted as a main control chip, an interface circuit board is utilized, and a multi-slot ISA bus interface is adopted to realize multi-channel synchronous data acquisition. The circuit design is designed according to 9 data acquisition channels of each AD acquisition board, 7 AD boards can be acquired simultaneously according to address allocation, and 63 paths of synchronous acquisition can be carried out, so that multi-channel synchronous data acquisition is realized.

B. Bluetooth transmission module

In order to control the cost of the tactile stick and reduce the power consumption, an HC-05 Bluetooth series communication module is selected and applied to wireless communication between the intelligent tactile stick and the Android mobile phone. During the period that the blind person uses the blind stick, the module returns the walking state of the blind person and the key indication state information of the blind person to the mobile phone end app so as to realize interconnection and intercommunication with the mobile phone end and the blind stick.

The module is based on a Bluetooth V2.0 standard data transmission module and uses an EDR protocol. The wireless working frequency is 2.4GHz ISM, and the modulation is GFSK. The module has a maximum transmit power of 4DBM, a receive sensitivity of 85DBM, and an antenna that provides 10 meters of communication. The module is sealed by a sealing aperture. The size of the module is 27 mm multiplied by 13 mm multiplied by 2 mm, which is convenient for being integrated into an application system. The module comprises an LED lamp, and the connection state of the Bluetooth can be directly determined. In addition, the chip used by the module supports AT instructions, a user can use flexibility to modify communication parameters such as the role (master-slave mode) of Arduino, the name of equipment, the baud rate of a serial port and the like according to needs, and the use is very flexible.

C. Intelligent obstacle avoidance module

The obstacle detection of the blind stick is divided into three-level safety distance, the obstacle detection at the front end is completed through an ultrasonic sensor, the first-level safety distance is set to be 70CM, and when the distance of the obstacle is smaller than the first-level safety distance, a buzzer module is triggered to send out a gentle alarm to indicate that an obstacle exists in the far front; when the distance is the secondary safety distance (50CM), a slightly short interval alarm is sent out, and when the distance is less than the tertiary safety distance (25CM), a very short interval prompt alarm is sent out.

D. Ultrasonic sensor

The system uses an HC-SR04 ultrasonic ranging module to measure the distance from the front barrier to the front barrier, wherein the distance from the front barrier to the front barrier is 2 cm to 4.5 m, so that the blind can detect the barrier and move the barrier conveniently. The ultrasonic detector module is used for detecting the obstacle in front of the blind person, and the following formula (1) is used for calculating the distance between the blind person obstacle and the blind stick, so that the blind person can effectively know the environment condition of the blind person.

d＝s/2＝(v×t)/2 (1)

E. Buzzer

The active buzzer is adopted to design the functions of sounding and reminding when encountering obstacles, mainly because the circuit design of the active buzzer is simple, and only one driving circuit is needed to sound, and fig. 3 is a driving circuit with the function of sounding the blind stick.

As shown in fig. 3, the PNP transistor serves as a switch for controlling the sounding of the buzzer. When the output of the IO port is low, the triode is in a cut-off state, and the buzzer does not sound; when the output of the IO port is high, the triode is in a conducting state, and the buzzer rings.

F. Danger signal detection module

According to the invention, the system automatically detects whether the blind stick falls or not according to the posture change of the blind stick. And a six-axis attitude sensor MPU6050 is adopted to measure the attitude of the blind stick. MPU6050 is equipped with a three-axis gyroscope and three-axis accelerometer and a vehicle Digital Motion Processor (DMP). The measurement accuracy of the acceleration sensor is 16384LSB/g (g represents the acceleration of gravity). The maximum operating current was 3.8mA, with I2C delivering up to 400 kHz. Through data fusion solving, the three-axis Euler angles can be solved.

The blind stick is simplified into a rigid body and is converted from an upright posture into an arbitrary posture which can be approximated by fixed point rigid body rotation, and the direction of any coordinate system can be expressed by three Euler angles for a reference system in a three-dimensional space. The reference system, also known as a laboratory reference system, is stationary. However, the coordinate system is fixed to the rigid body and rotates with the rotation of the rigid body. The xyz axis is set as the reference axis of the reference frame. The intersection of the XY plane with the XY plane is called the intersection line and is denoted by N. One euler angle can be statically defined as follows:

angle of x axis to α

Beta is the angle between the z-axis and the z-axis

Gamma is the angle between the intersection and the X-axis

According to the change of the absolute value of the beta (the Z axis is vertical to the horizontal plane), whether the blind stick falls down can be effectively judged.

2. Software design

The software part of the system adopts a modularized thought, and is divided into the following parts according to different functions: the system comprises a one-key navigation function, a falling location help-seeking function, an emergency telephone short message function and a trip weather forecast. The system adopts Android Studio to develop software end APP, and controls abundant functions of the software end by using keys of the hardware end based on the Bluetooth function. The software part is designed based on different functions, and Android Studio which is excellent in intelligent code input, code reminding, J2EE, code checking, CVS integration and the like is selected as an intelligent APP development environment.

A. One-key voice navigation and navigation home

Due to the particularity of the travel of the blind, the navigation is carried out in a voice broadcasting mode. When the blind presses a key of 1 button for navigation at the hardware end, the hc-05 transmits a signal '1' to the app at the mobile phone end, and the software end can realize voice navigation based on the Baidu map SDK by directly calling the Baidu map uri api.

The code and its parameters of the smart APP using the Baidu map URI API are described as follows:

intent bxdh1 ═ new Intent (); navigation for the blind

bxdh1.setData(Uri.parse("baidumap://map/walknaviorigin＝56.857568942722,101.56482107654&destination＝33.85641,109.46505&src＝andr.baidu.zhidaoAPP&coord_ty pe＝bd09ll"))；

startActivity(bxdh1)；

TABLE 1 parameter description of pedestrian navigation in Blind-guiding APP

The function of navigating to the home is mainly designed for the convenience of blind operation, the principle of navigating to the home is consistent with the programming principle of walking navigation, and the function of navigating to the home by voice can be realized by pressing 2 keys at the hardware end. Blind guide APP uses the code of the Baidu map URI API:

an Intent dj ═ new Intent (); // guide the blind to go home

dj.setData(Uri.parse("baidumap://map/navi/commonaddr＝home&src＝andr.baidu.zhidaoAPP&coord_type＝bd09ll"))；

startActivity(dj)；

B. Falling location help-seeking

When the blind stick is in a falling state for a long time, the falling location help-seeking function takes the Android system as a carrier, the GPS carried by the mobile phone is used for locating the blind person, and when the APP receives a dangerous signal, the system can automatically send the blind person position information to a designated contact person in a short message mode. The intelligent guiding APP selects GPS positioning, the positioning principle is that information such as current longitude and latitude is acquired based on the direct interaction information between GPS hardware existing in the mobile phone and communication hardware on a satellite, the mode is high in precision, the corresponding APP positioning API selects Android positioning SDK provided by a Baidu map developer platform, and the position information is sent by directly calling a mobile phone system.

The blind stick pose change can be estimated using IMU (inertial sensors), i.e. accelerometers and gyroscopes. The specific process is as follows:

assume that there are two measurement methods for an angle signal y (t):

z_1(t)＝y(t)+n_1(t)

z_2(t)＝y(t)+n_2(t) (2)

where n _1(t) and n _2(t) are measurement noise. It is desirable to weight average z _1(t) and z _2(t) so that the error after averaging is as minimal as possible. In the attitude estimation of the IMU, if z _1(t) is considered to be an angle obtained by integrating a gyroscope, z _1(t) is accurate in a short time, but the precision is greatly reduced due to drift errors after a long time, namely n _1(t) is mainly low-frequency noise; if z _2(t) is considered to be the angle that the accelerometer obtains by a solution in comparison with gravity, then z _2(t) is inaccurate in acceleration due to motion for a short time, but the IMU cannot accelerate in one direction for a long time, so the average value of z _2(t) over a long time is accurate, that is, n _2(t) is mainly high frequency noise. One natural idea is therefore: z _1(t) can be passed through a high pass filter to filter out low frequency noise; passing z _2(t) through a low pass filter to filter out high frequency noise and averaging, the result should be accurate. This is the core idea of the complementary filter and why it is called "complementary".

If z _1(t) and z _2(t) are Laplace transformed and written as signals in the frequency domain, and G(s) represents a low-pass filter, averaging the two signals can obtain:

{Y}(s)＝Z_1(s)[1-G(s)]+Z_2(s)G(s) (3)

where Y(s) is the estimate of the angle signal Y (t) to be measured, and 1-g(s) is a complementary high pass filter. Since z _1(t) is an integral of angular velocity, it can be written as:

z_1(t)＝\int_0^t\omega_\text{true}(t)+n_\omega(t)dt＝\int_0^t\omega(t)dt(4)

where \\ \ omega (t) is the measured angular velocity containing the error. Substituting (4) into (3) can obtain:

\hat{Y}(s)＝\frac{\Omega(s)}{s}[1-G(s)]+Z_2(s)G(s) (5)

if the simplest first-order low-pass filter is used, i.e., g(s) \ frac { k } { s + k }, substitution (5) to clean up and inverse Laplace transform back to the time domain can result:

s\hat{Y}(s)＝\Omega(s)+k[Z_2(s)-\hat{Y}(s)]

\dot{\hat{y}}(t)＝\omega(t)+k[z_2(t)-\hat{y}(t)] (6)

and then (6) is integrated to the first order to obtain:

\hat{y}_{n+1}＝(1-k\Delta t)\hat{y}_n+k\Delta tz_{2,n}+\omega_n\Delta t (7)

equation (7) is the expression of the complementary filter in the time domain. It can be seen that the complementary filter actually performs weighted averaging on the angle obtained by integrating the gyroscope and the angle solved by the accelerometer, and the weights are 1-k \ Delta t and k \ Delta t respectively. It should be noted that the weights are not time-varying, which is a substantial difference between the complementary filter and the kalman filter. Intuitively, because the noise characteristics of the accelerometer do not change over time, but the angle integrated by the gyroscope becomes more and more accurate as the filtering proceeds, the weight obtained by z _2(t) in the kalman filter becomes smaller and smaller, which is why the kalman filter is better than the complementary filter. Such a simple one-dimensional complementary filter also has practical application in IMU pose estimation. For example, in a two-wheeled balance car, only the angle at which the balance car is tilted needs to be estimated, so the attitude can be simplified to a one-dimensional angle, and an accelerometer and a gyroscope are used for estimation.

c.GPS positioning

The intelligent guiding APP is built by taking an Android system as a carrier, the Android system contains an interface support of GPS positioning, and sdk-hundred degrees of a third-party company which is well made in China can be used. By utilizing the Baidu LBS SDK, the intelligent guide APP can determine the longitude and latitude of the current position of the blind person at any time and acquire specific province, city, district, street and other addresses. Fig. 4 is a flow chart of the positioning function programming.

As shown in fig. 4, first, environment configuration of the smart APP + key acquisition is performed: before the development work starts, a Baidu map developer platform needs to be logged in to obtain AK, and project environment is configured. Copying the previously downloaded Baidu map location SDK into project of the wisdom leader APP; then, initializing the smart APP: declaring an object of the LOCATIONCLIENT class in the main activity and introducing a parameter of Context when initializing the object; then, configuring parameters of the Baidu map positioning SDK according to the requirements of the blind: setting a continuous positioning mode, selecting a longitude and latitude coordinate as BD09ll, selecting a positioning mode as selectable, and calling a locationClientOption class for SDK parameter selection of positioning; there are three positioning modes: the blind person can select the power-saving mode positioning, the accurate mode positioning and the outdoor mode positioning according to the actual scene; the Baidu map can select three coordinate types, namely BD09, GCJ02 and BD09 ll; then, the monitoring and positioning interface is realized: from version V7.2 of the Baidu map, the SDK of its location provides an abstract interface to the outside, named bdabstrattocitoncinolite, for location monitoring. The old bdlocatelistern is temporarily retained and suggests the developer to switch to a new abstract interface that generates location results in an asynchronous manner; finally, only positioning needs to be initiated, and a position result can be obtained from the BDABSTRACTOTONLISTER monitoring interface.

D. Short message help seeking

And designing a help-seeking short message function, namely selecting to directly call a sms interface with a short message function of the Android system to send a short message, wherein the content of the short message is a help-seeking signal together with the detailed address information obtained from the last step, and a contact person sending the short message is a telephone number which is input by a blind family member in a dialog box in the intelligent guide app in advance. Fig. 5 is a flow chart of the help-seeking short message function.

E. Travel weather forecast

In order to facilitate the blind people to know the weather conditions in time, the system adds a weather broadcasting function, the blind people can set fixed time for voice broadcasting of the weather conditions, and can also know the weather conditions at any time through the external buttons of the blind stick. This function is also implemented by directly calling the smart application and the cane foreign key of the Baidu map uri api.

The blind guiding APP uses the codes of the Baidu map URI API and the parameters thereof are explained as follows:

the Intent tqi ═ new Intent (); v/Accent weather forecast Page

tqi.setData(Uri.parse("baidumap://map/newsassistantsrc＝andr.baidu.zhidaoAPP"))；

startActivity(tqi)；

TABLE 2 parameter description of weather forecast in Blind guide APP

While the invention has been described with respect to a limited number of embodiments, those skilled in the art, having benefit of this description, will appreciate that other embodiments can be devised which do not depart from the scope of the invention as described herein. The present invention has been disclosed in an illustrative rather than a restrictive sense, and the scope of the present invention is defined by the appended claims.

Claims (10)

1. The blind person trip assisting system is characterized by comprising a blind stick end and a moving end, wherein the blind stick end and the moving end are communicated in a wireless mode; wherein the content of the first and second substances,

the blind stick end comprises a data acquisition module, a main control module, an alarm module and a key instruction acquisition module;

the data acquisition module comprises an obstacle distance data acquisition submodule and a blind stick posture data acquisition submodule; the obstacle distance data acquisition submodule is used for detecting distance data between an obstacle and the blind stick and sending the distance data to the main control module; the blind stick attitude data acquisition submodule is used for acquiring attitude data of a blind stick in real time and sending the attitude data to the main control module;

the main control module comprises an obstacle avoidance reminding sub-module and a blind stick falling detection sub-module; the obstacle avoidance reminding submodule is used for comparing the distance data with different distance thresholds and sending different obstacle avoidance alarm information to the alarm module; the tactile stick falling detection submodule is used for fusing and solving the attitude data to obtain a three-axis Euler angle, and sending a falling signal to the mobile terminal when the Euler angle changes;

the alarm module carries out early warning in different forms according to different obstacle avoidance alarm information;

the key instruction acquisition module is used for acquiring a cane end key instruction and sending the key instruction to the mobile end; the key instruction comprises a voice navigation instruction;

the mobile terminal comprises a voice navigation module and a falling location help-seeking module;

the voice navigation module is used for calling a network map service to perform voice navigation after receiving a voice navigation instruction sent by the tactile stick end;

the falling location help-seeking module comprises a falling state judgment submodule, a GPS (global positioning system) positioning submodule and a help-seeking information sending module; the falling-down state judgment submodule is used for judging whether the blind person is in a falling-down state according to a falling-down signal sent by the blind stick end, and calling the GPS positioning submodule to acquire the current position of the blind person under the condition of judging that the blind person is in the falling-down state; the distress message sending module is used for sending the position of the blind and distress messages to the designated contact person.

2. The travel assistance system for the blind according to claim 1 wherein the obstacle distance data collection submodule is an ultrasonic sensor, and the distance threshold is divided into a primary safety distance, a secondary safety distance and a tertiary safety distance.

3. The blind person travel assisting system according to claim 2, wherein when the distance data in the obstacle avoidance reminding sub-module is smaller than or equal to a first-level safety distance, obstacle avoidance alarm information is a gentle alarm; when the distance data is smaller than or equal to the secondary safety distance, the obstacle avoidance alarm information is used for sending interval long alarm; and when the distance data is less than or equal to the three-level safety distance, sending out short-interval and urgent alarm by the obstacle avoidance alarm signal.

4. A blind person travel aid system according to claim 3 wherein the distance threshold values comprise a primary safety distance of 70CM, a secondary safety distance of 50CM and a tertiary safety distance of 25 CM.

5. The blind person travel assistance system according to claim 4 wherein the alarm module is an active buzzer; the blind stick attitude data acquisition submodule is a six-axis attitude sensor MPU 6050.

6. A blind person travel aid system according to claim 5 and wherein said wireless means is Bluetooth.

7. The system of claim 6, wherein the key commands sent by the blind stick terminal further include a weather forecast playing command; the mobile terminal also comprises a weather forecast playing module, and the weather forecast playing module is used for calling a network map and a weather forecast service function to play the weather forecast after receiving a weather forecast playing instruction sent by the cane terminal.

8. The travel assisting system for the blind as claimed in claim 7, wherein the obstacle distance data collecting submodule is a monocular camera module, and the monocular camera module detects the distance between the obstacle and the blind stick by using the collected image data.

9. The system of claim 8, wherein the monocular camera module detects the distance between the obstacle and the blind stick by using the collected image data in a specific process: acquiring an obstacle imaging picture through a monocular camera, wherein the monocular camera is arranged at a fixed position of the tactile stick, and an optical axis of the monocular camera is parallel to the ground; acquiring the height H and the image distance f between the monocular camera and the ground level, and acquiring the coordinates (x, y) of the obstacle according to a first coordinate system with the center of the obstacle imaging picture as an origin; calculating the horizontal distance d between the obstacle and the monocular camera according to the following formula:

compensating the horizontal distance according to an image distance error formula and/or an incident error formula of the monocular camera to obtain an actual distance; and parameters and the installation position of the monocular camera are fixed.

10. The blind person travel assistance system as claimed in claim 9, wherein the blind-stick end adopts an arduino main control chip to realize the functions of each module of the blind-stick end.

Images