Intelligent crutches scheme design and development
1. Hardware design of smart crutches
1.1 Principle of system function realization
The multi-function smart crutches mainly use single-chip technology, and are a kind of smart retractable crutches with multi-functions such as infrared distance measurement, alarm and tilt. The intelligent crutches hardware is mainly composed of angle sensor, pyroelectric sensor, buzzer, 89S52 single chip microcomputer control circuit.
1.2 Hardware circuit design
(1) The working principle of the SCA60C angle sensor: This design uses the 89S52 single-chip microcomputer as the control core, and uses the SCA60C single-axis tilt sensor to measure the balance state of the crutches. When the crutches are in equilibrium, the angle sensor SCA60C is at 0° to the horizontal plane, and the analog voltage of 0.5V is output from the Vout terminal. When the crutches are perpendicular to the ground, the angle sensor SCA60C is at 90° to the horizontal, and at this time Vout outputs an analog voltage of +5V. The sensor SCA60C can only accurately detect the range of 0~90°. Within this range, the analog voltage signal of +0.5V~+5V output at the Vout terminal is proportional to the size of the inclination angle, so the output terminal Vout of the sensor SCA60C can be determined by The magnitude of the voltage can determine the angle between the crutches and the horizontal plane.
(2) Driving principle of buzzer: The electromagnetic buzzer is mainly composed of oscillator, electromagnetic coil, vibrating diaphragm, magnet and housing. After the power is turned on, the audio signal current generated by the oscillator passes through the electromagnetic coil, which causes the electromagnetic coil to generate a magnetic field. The vibration diaphragm periodically vibrates under the interaction of the electromagnetic coil and the magnet to produce sound. Because the buzzer needs a certain current to drive it, the output current of the single-chip I/O pin is small, so the single-chip output TTL voltage cannot basically drive the buzzer, so the amplifier buzzer is driven by adding a triode.
(3) Working principle of human pyroelectric infrared sensor: pyroelectric infrared sensors are all pyroelectric infrared sensors based on the principle of thermoelectric effect. The human body has a constant body temperature of about 37°, so it will emit infrared rays of about 10 μm to work of. The infrared ray of about 10μm emitted by the human body is enhanced by the Fresnel filter and concentrated on the infrared induction source. The infrared induction source uses a pyroelectric element, which loses its charge balance when the temperature of the infrared radiation received by the human body changes. To release charge outwards. Once the human body enters the detection area, the infrared radiation of the human body is focused through a part of the mirror surface, and is accepted by the pyroelectric element. After being processed by the single-chip microcomputer, an alarm is generated.
2. Smart crutches software function
The intelligent crutches software part mainly includes: initial setting, establishing GPS positioning, online monitoring, electronic fence, family number setting, help and other functions.
(1) Software block diagram design: The guardian can enter the software interface through the web terminal or mobile phone client. If it is the first time to use, the initial setting is performed first. Fill in the relevant content according to your own situation and judge whether the GPS positioning function installed in the crutches is turned on. If it is turned on, you can know the position of the crutches at this time according to GPS positioning. When the crutches are tipped, the buzzer in the hardware circuit is turned on An alarm is issued; when more than 1 minute, the motor automatically dials the preset phone through the hardware circuit to get further help. You can also set an electronic fence in the interface, and when it exceeds the set range, it will give an alarm prompt.
(2) Call settings: This setting can set up to 4 numbers, users can set the number according to their own needs, SOS button can set emergency calls.
(3) GPS positioning function: GPS positioning is divided into two parts: online monitoring and electronic fence setting. The online monitoring function can be located in three ways: map, satellite and three-dimensional.
3. The design of the appearance of smart crutches
(1) The crutches are designed with aluminum alloy telescopic rods, the height can be adjusted from 65cm-98cm, and the weight is 320g, which is suitable for more people. Usage: Press the button on the aluminum alloy rod by hand, move the thinner aluminum alloy lower rod up and down, and buckle the button into the corresponding hole position of the thicker aluminum alloy rod to meet the needs of people of different heights, height adjustment When it's ready, tighten the lock ring.
(2) Illumination and flash usage: Push button switch on the top of the handle. Operation mode: switch first gear, white LED lighting; second gear, white LED lighting + red LED flash warning; third gear, off.
(3) MP3 function usage: Use your finger to gently press the MP3 control button on the middle of the side of the handle, MP3 is in working state. At this time, lightly press the left and right buttons with your finger to realize the selected music. Use your finger to lightly press the MP3 up and down volume control buttons to adjust the sound level and listen to music at a suitable volume level.
(4) Charging usage: insert the charging end into the DC port of the product, and connect the other end to the standard 5V output USB female seat to charge the internal rechargeable battery. At this time, the charging red indicator light is on, and the indicator light is off after being fully charged.
(5) Usage of GPS positioning, telephone, and alarm function: Turn on the GPS positioning function switch of crutches to realize the positioning function. The guardian can log in the GPS positioning platform through the web and mobile client to view the specific location of the user. At the same time, you can dial the preset phone through buttons 1, 2, and 3. The guardian can also dial the phone card number built into the crutches to answer the call by connecting the phone. When the crutches fall, the buzzer automatically sounds an alarm sound, and when a person leaves the crutches, the buzzer sounds a drip prompt.
to sum up
This design studies the psychology and physiology of the elderly, and designed this model with diverse functions, novel technology, and strong market targeting. Through the test of the prototype, the following functions are mainly achieved:
(1) GPS positioning function, the guardian can determine the specific location of the user at any time. The guardian can monitor the user's activity track through the GPS positioning interface to realize continuous real-time positioning. (2) The guardian can set up an electronic fence. When it exceeds the set range, the alarm function is turned on. If necessary, the guardian is called to send out help information. (3) When the crutches are tipped and the buzzer is turned on, for more than 1 minute, the guardian or SOS signal will be called to get timely help. (4) LED lighting, MP3, telescopic and other basic functions.
The design uses a rubber handle that conforms to the human-machine curve, which provides maximum safety and comfort during use. With the development of society and the improvement of living standards, it is the general trend to care for and improve the quality of life of the elderly. The design has full functions, light weight, simple operation, reliable use, and low cost. It can meet the purchasing power and functional needs of ordinary people and has a broad market expectation.