This article introduced a section uses the PIC16F74 monolithic integrated circuit to take the micro processing chip the electrically operated massage armchair control system, includes system’s composition and the function specifically introduced that hardware circuit’s design, the software function realize as well as the antijamming measure.
1: Introduction
Along with our country economy’s rapidly expand and the people living standard’s unceasing enhancement, health products and so on massage armchair receive welcome more and more. At present, in electrically operated massage armchair market, import, joint capital as well as domestically produced product coexisting. Relatively speaking, the imported product function is formidable, the massage way is rich, the outward appearance is exquisite, but its price is also simultaneously expensive. But the domestic product function is simple, the product popularity relatively is also low, but its price is quite inexpensive. This article mainly introduced a section of independent research and development middle-grade electrically operated massage armchair. This product already has the function to be quite formidable, the massage way to be quite rich, the structure to be simple, the outward appearance is exquisite, control mode simple nimble, the product easy to promote characteristic, simultaneously its price actually only then overseas same level product half.
2: The massage armchair system’s composition, the principle of work and the function realize
2.1: System composition
The overall system mainly divides into two parts, namely the back massages the region and the buttocks, the lower limb massages the region.
The back massages the region the organization mainly to have: The systems control circuit wafer, the electric motor, the lead screw and the lubricating arrangement, the S shape glide trough, the massage first-class honor can the box and so on. Meanwhile according to body constitution back entire regionalism for pate, middle, waist as well as coccygeal vertebra four massage sectors. But the buttocks, the lower limb massage the region the organization mainly to have 12
The massage aerocyst and realizes the organization. In addition the system mainly also has the manually controlled kneading board, the infrared acquisition system, the seat back cushion, a calf place electrically operated throwout lever and so on.
2.2: System principle of work and structure function characteristic
Because the PIC monolithic integrated circuit has the cost to be low, the function is rich, control mode simple and so on superiority, therefore the system uses the PIC16F74 monolithic integrated circuit to take system’s control chip.
System design for automatic and manual two kind of movement pattern. Under the automatic pattern, the massage pattern mainly has: The fast relieve fstigue pattern, the leisure pattern, the sleep pattern as well as suit the gentle pattern which Mr. Yu uses and so on. But under the manual way, may open stops the random electrical machinery and the massage aerocyst. And may act according to the actual situation, the massage dynamics which, the width and the aerocyst massage pressure the choice needs. The system all massage function has the third speed adjustment.
The back organization basis human body’s back physiology curve design is the S shape structure scientifically. His/her the back organization’s major function includes: The massage, rubs pinches, thrashes and the shiatsu. And the massage, rubs pinches, thrashes and the shiatsu function realizes separately by three electrical machinery individual drives. The massage first-class honor can the box be possible to move up and down, and may choose the entire journey, partial as well as the fixed point carries on the massage. But in the buttocks and the lower limb region, may take in and put away the fluctuation rhythm as well as the aerocyst intensity through the control aerocyst realizes the massage.
In addition may also act according to individual likes controlling the seat back cushion, a calf electrically operated throwout lever, adjusts the seat back cushion and the calf angle of tilt, thus enhancement massage comfort level.
2.3: The system function realizes
2.3.1: The hardware realizes
In this massage armchair control system’s main hardware is the PIC16F74 microprocessor. The electric power supply is 5V, the input and the output may be the simulation (quantity) the signal, may also be the switch (quantity) the signal. What this control system uses is the PIC16F74 switch quantity input and loses carries on the control.
The system first obtains the massage object through the infrared acquisition installment the height and the physique parameter, and will be related the parameter to transmit for the system master routine, then the basis human body acupuncture point’s distributed principle, the actuation massage organization carries on the massage.
In system’s back traveling schedule and rubs pinches the electrical machinery when the movement needs to commutate frequently, its is reversing the function to use the interlock electric circuit to actuate two relay work to realize alternately, and the electric circuit are at any time most only then a relay work, like this may very effective avoid the identical relay after the long time use, after its commutation the bad contact causes electric circuit short circuit situation, thus may enhance the systems operation greatly the stability and the reliability, obviously lengthens the product the service life.
2.3.2: The system software realizes
To display system’s performance fully, realizes the massage way, dynamics and the width reasonable combination, this system software altogether design is three: Motor-driven level, function actuation level, user interface. And: The motor-driven level is responsible for hardware’s actuation, namely stops, the strong and the weak as well as the width actuation; The function actuation level is responsible for all functions according to the priority arbitration, carries on the protection or the elimination to the preliminary function, and with other module function level junction equivalence; But the user interface is responsible to receive the user the pressed key input. Its principle as shown in Figure 1.
System’s control procedure flow chart as shown in Figure 2
On after system electricity, CPU starts to the entire keyboard to carry on the scanning, when after scanning some key presses down, carries on the suitable time delay to disappear shakes, confirms the pressed key effectively after once more, is the start corresponding pressed key’s service subroutine, then carries on the zero crossing detection, through controls the silicon-controlled rectifier to realize to electrical machinery’s speed control. Meanwhile electrical machinery’s speed condition demonstration in LCD.
This system software has mainly solved the following several important problems:
2.3.2.1: Zero crossing detection
The system use specific hardware circuit carries on the rectification after the city electricity obtains the half-wave signal, then from RA4 pin input synchronized signal. The system ingenious has used hardware’s characteristic, when carries on the starting value hypothesis after T0, then triggers timer T0 through the external signal the turn over, thus realizes the precise zero crossing detection. Then may control the silicon-controlled rectifier according to the zero crossing detection to realize to the electrical machinery voltage accuracy control. The error which very effectively through the software this may avoid carrying on when zero crossing detection brings, and causes from the electrical machinery voltage control inaccurate, unstable as well as the overall system movement is unreliable.
2.3.2.2: Massage sector division
After the infrared acquisition installment surveys the massage object the corresponding parameter, the procedure acts according to this result the entire massage regionalism for the pate, middle, the waist as well as the coccygeal vertebra four sectors. And selects the different massage method and massage dynamics and the width change combination according to the human body physiology principle to each sector, thus enhancement massage comfort level.
2.3.2.3: Pulse counting
The procedure uses the CCP module (i.e. capture, comparison, pulse width modulation module) the capture function to realize the pulse counting. Thus realizes the massage first-class honor to be able the box in sector motion control. But in the experiment process discovered that the counting value occasionally will have the error. After taking the following corrective measure: Namely when after CCP catches the first pulse, then immediately closes CCP, after simultaneously starts the timer and time delay certain time, starts CCP to continue again to carry on the pulse counting. After the long time’s experiment determination as well as the user feedback’s situation, determined that uses the pulse counting which CCP realizes already to be very accurate, has met system’s control precision requirements completely.
2.3.2.4: Traveling schedule control
The traveling schedule electrical machinery has the hardware protection circuit, has the limit switch in the traveling schedule head and tail installment, when after the function box bumps into the limit switch, by limit switch cut-off traveling schedule electrical machinery’s power supply, and causes pin RB5 and the RB4 level fluctuation. Therefore the procedure may controls electrical machinery’s commutation through examination pin RB5 and the RB4 level fluctuation. But because limit switch after use long time possibly will present the malfunction the situation, by now the function box even if moved the high and low limit switch, also will not cause pin RB5 or the RB4 level fluctuation, when will have this kind of situation, because the procedure has not examined the commutation signal to control the electrical machinery to continue to the unidirection movement, until will go against dies in lead screw’s limiting position.
In order to avoid the product having this kind of situation in the use, in
In the control traveling schedule electrical machinery commutation’s procedure, increased has controlled the electrical machinery commutation according to the traveling schedule counting value the function: Designated that then the down stroke spacing takes the counting basic point extremely, after the traveling schedule electrical machinery starts, starts to carry on the pulse counting, and uses the fluctuation counting value separately in the ascending-descending direction the method, when the traveling schedule counting value achieves the hypothesis the limit value then carries on the commutation, but when the function box each time arrives at the counting basic point to the counting value carries on the reset again.
Through uses controls the electrical machinery commutation after the traveling schedule counting value, according to the experimental result as well as the user feedback’s situation, after taking the above measure, may remarkable enhance the systems operation the stability and the reliability, thus improved the product quality, lengthened the product service life.
3: System antijamming measure
For guarantee system’s normal work, when design has used below some antijamming measure: In hardware aspect, because the system is high to the power source request, therefore when designed the power source has used the multistage constant voltage performance good 7805 modules; Also because in this system monolithic integrated circuit’s input signal is the switch quantity, therefore increased extremely in each input circuit’s input end one extremely anti- has accommodated the filter by the interference protection; Moreover the system used the reset function to prevent the procedure to enter the endless loop. In addition has also taken some antijamming measure in the software aspect, for instance when the electrical machinery commutates used certain time delay to protect the electrical machinery, when after CCP caught the effective impulse signal, after closing CCP and time delay certain time, started CCP again, reduced the capture to harm pulse and so on.
4: Conclusion
The system uses the PIC16F74 monolithic integrated circuit to take the micro processing chip, realizes to the electrically operated massage armchair’s control. Through increases the essential interlock electric circuit in the hardware circuit, enhanced the systems operation stability and the reliability, and has realized the accurate zero crossing detection using the system hardware characteristic, thus has provided the good prerequisite for the electrical machinery voltage’s accuracy control and the stabilizing adjustment; In the software, increased has carried on the reverse control according to the traveling schedule counting value, as well as used the interrupt mode to realize to the electrical machinery the control and so on. Above after using some measures, not only reduced the control section production cost, moreover reduced the product development cycle, has guaranteed the systems operation stability, the reliability as well as the economical usability.
Reference
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