Source of creativity:
The blind leading stick is a tool most commonly used by the blind. The traditional blind leading stick cannot meet the blind’s travel demand anymore. The blind urgently need a smart blind leading stick. Thus, we come up with an idea to design the smart blind leading stick.
A Detection of non-contact barriers: Surrounding barriers not contacted can be sensed.
B Three-dimensional detection: This product is equipped with three sensors located at the left, center and right. The sensors at the left and right are infrared detector switches, and the sensor at the center is the ultrasonic obstacle-avoiding module. The sensor at the center prompts the blind by voice, and the sensors at the left and right detect obstacles at the left-right direction and prompt the blind through a vibration device on the stick. Three sensors form a sensor cluster, avoiding the dead zone of blind leading at certain direction and angle.
C Turn reminder: If needing to turn during walking, the blind may press the left/right turn button to switch on the turn light on the stick to remind passers-by of turning.
D Automatic leveling: The three-dimensional detection head of smart blind guiding stick is provided with automatic leveling function. Different blinds have different using habits, so the included angle generated between the blind leading stick and ground may be also different. However, the detection head can be always kept level with the ground.
E One-key seek: This smart blind leading stick is equipped with a smart seek key ring. In case the stick cannot be found, the blind may press the seek key to quickly find the blind leading stick.
DIP switch *1
7.4V battery *1
3.7V battery *2
a Circuit connection:
The stick includes Arduino Uno as the main controller and 2 infrared digital obstacle-avoiding sensors as the obstacle-avoiding monitoring terminal and adopts ultrasonic distance measurement. Two vibration modules transmit the obstacle information at the left-right direction. Two buttons are matched up with two LED to allow the blind to remind the passers-by when turning. The specific circuit connection is as follows:
b Code writing:
Modeling and installation:
A flexible mop rod is selected as the main body of blind guiding stick, including sensor part, main controller part, input & perception part. Such three parts of main body of stick are integrated.
The design models are as follows.
A mop rod is disassembled and our main controller shall be installed on the rod top, so a connection part is designed to connect mop rod with the main control box
Figure 3 Connection Part Model
Figure 4 Picture of Connection Part
Figure 5 Installing the Connection Part at the Mop Rod Head
If feeling it is hard to insert the rod head into the connection part during installation, you may install it again after warming it with hot water.
Figure 6 Model of Main Controller Box
Figure 7 Model of Main Controller Box Cover
Figure 8 Figure 9 Fastening the Connection Part with Main Control Box with 4 Screws
After the main controller box is installed, holes shall be drilled at the appropriate position of the main controller box. The initial idea is to insert the connection line in the mop rod, but we do not have appropriate tools to drill holes on the metal surface. Thus, we decide to conduct wiring on the surface of rod temporarily. Place the main controller and relevant sensor electronic parts in the main controller box and thread the connection lines from hole.
Figure 10 Threading Lines of Infrared Obstacles-avoiding Switch from Hole
Figure 11 Placing and Fixing the Main Controller in the Box
Figure 12 Drilling Holes and Correctly Installing LED Indicators
Figure 13 Threading Relevant Sensor of Input& Perception Part from Box Cover Hole
At the sensor part, a waterproof ultrasonic switch and two infrared switches are used to form a multi-angle detection cluster. To integrate the sensor with the mop rod, we design a fixed clamp and a sensor box.
Figure 14 Fixed Clamp
Figure 15 Sensor Box
Figure 16 Sensor Box Cover
Figure 17 Installing the Sensors at the Appropriate Position (ultrasonic sensor at the center and infrared obstacle-avoiding switches at the left and right).
Figure 18 Fixing the Sensor with Hot Melt Adhesive from the Interior Position of Box after Installation
Figure 19 Installing the Input & Perception Devices (Turn Button, Left/Right Vibration Prompter and Buzzer) at the Handle Part
Figure 20 3D Model of Handle
Figure 21 3D Printing Handle
Drill holes on the handle for installing electronic components above.
Figure 22 Overall Effect after Installation
Figure 23 Test of Turning Function
Two Bluno Beetle controllers are used for one-key seek function. The communication between the master and slave controllers is realized through wireless Bluetooth. Please refer to making of Bluetooth control switch for the master-slave setting of Bluetooth module.
Figure 24 Circuit Connection of Bluetooth Master Control Terminal (Key Ring Terminal)
Figure 25 Picture of Bluetooth Master Control Terminal
Figure 26 Circuit Connection of Bluetooth Controlled Terminal
Figure 27 3D Model Design of Controlled Terminal
To improve the integration level of product, we place the controlled terminal of Bluetooth at the tail of stick handle. The controlled terminal is relatively independent of smart stick in respect of circuit.
read original artical:https://www.dfrobot.com/forum/viewtopic.php?f=2&t=2905